I had the idea and it simply wouldn't go away so I wrote it for you all. Enjoy!
I don't own Sherlock, it belongs to the BBC.
Drugs
John was only gone for a week but it was a week none-the-less. It just so happened that this week there had been no cases of interest, or at least to Sherlock, but he might have even taken on the easier and most simple of cases if they had been offered to him, but the point standing was that they hadn't been. No cases sent through to him, all of them being solved without his input and he was bored. His mind whirring and not stopping. He couldn't stay still and he couldn't stay focused. He needed something to do however without any cases and without John there wasn't much for him to do.
John was only in a couple cities across doing some sort of new training for Barts or something. What he was doing was irrelevant, unless of course he was in danger (that would be something t do, he thinks, but then decided that he wouldn't be able to handle it if John was in danger again so decides to stop think about it). He would be home in a few days, back to domestic life and, of course, solving crimes with him.
But in his bored mind a few days seemed like an infinite infinity, which he was too distracted to realise that that analogy was in fact paradoxical, and he decided he just could not wait any longer and phoned Lestrade. After a few missed calls Sherlock gave up. He simply didn't have the patience to wait for him and he needed something to do now. Through the haze of boredom he had a thought, old habits die hard and he soon finds himself deducting the clues pointing himself to where his stash had been hidden this time. Not long after he's sat in the bathroom floor, his make-shift tourniquet in place and the needle piercing his vein. The fog lifts instantly and he's soon finding something to do with himself, for the first time in days not bored.
He should have know that Mycroft would know about it. He wasn't discreet about it, doing it in plain sight in his bathroom with doors unlocked. He most definitely didn't think of John either. But he knew there was no hiding it when he had a drugs squad barging through the doors and scanning his apartment for any other substances later in the day. He's silent all through though and doesn't protest. He knows that he had messed up, despite the fact that Sherlock Holmes does not make mistakes. So when Mycroft makes an appearance himself he asks, not begged -definitely not begged- Mycroft to not tell John of what had happened and to his surprise Mycroft agreed.
Having removed all possible substances that Sherlock could abuse, of ranging legality, Mycroft leaves along with his drugs squad, leaving no sign of having been there in the first place. Sherlock simply sits on the sofa, sleeve still rolled up from earlier and vows to never let John know what had happened that day and swore he would keep calling Lestrade next time -because so help him there would definitely be a next time- he would not make the same mistake again.
Eating
Sherlock has always had a problem with his eating, even when he was child. He said that digesting food slowed his thought process, which was vital to avoid most of the time. But of course it was only a cover. He knew what he saw in the mirror -every mirror really- and despite the fact that he knew that logically it didn't make sense he knew that he just had to trust what he saw. The overly pudgy hands and arm, slightly too round torso, the much too puffy legs, it was all too much. That was why he did it.
He counted every calorie almost automatically, working out how much he would gain and lose systematically and yet never seeming to lose it off of his figure. He tried all that he could, sometimes going weeks on nothing but water, relishing the feeling of emptiness and the rush he got when he stood up too quickly, analysing the seconds between consciousness and unconsciousness, It was all a game to him, an experiment layered over self loathing. Really nothing more than a weak excuse.
Then John came into his life, the doctor quickly picking up on his habits but not saying anything, chalking it up to just Sherlock being Sherlock, simply placing more food in front of him, calorie after calorie, Sherlock's mind never stopped counting each intake, but not wanting to upset John he ate it all, quickly and mechanically and once having finished simply expelling the content of his stomach into the toilet bowl, his teeth scraping his knuckles on the way in and out.
This happened every time that John gave him food, he would eat it then expel it and never losing the precious few pounds that would finally make his beautiful enough to be loved. The vicious cycle continued.
Self harm
It wasn't about death, Sherlock told himself time after time, whilst sat alone in the witching hours of the morning watching the deep red run across his arm and drip onto the tissue so lovingly placed beneath. He always took extra care to make sure that there was no evidence of his nightly activities other than that neat red lines marking his skin. No it wasn't about death or even pain it was just that he was addicted to seeing the flesh split open and blood pool in the welt, he found perverse attraction to the crimson liquid, watching as it made sick lines on his pale skin.
Sighing he wiped up the remnants of his hobby and swiftly disposed of the tissue down the loo and simply staring at his own reflection in the mirror. Dark circles swallowing his eyes, cheeks gaunt yet caked with fat. He couldn't handle it truly, the weight of his intellect pushing down on his shoulders, weighing him down until he snapped and needed to prove that he still existed, that he wasn't just a consciousness trapped in a metal body hidden under paler skin and dark curls.
He knew that their words shouldn't have this effect on him.'Caring isn't an advantage' as his brother was wont to say, and in this moment he was inclined to believe him. He shouldn't hurt like this, these words shouldn't cause physical pain yet they do. A tear slips down his cheek and he wasn't sure that when he looked up if he would see water or oil leaking from his eyes.
A small noise, hesitation and then a knock alerts him to John's presence and he straightens his back, wiping away a stray tear and schooling his face. He strides over to the door and opens it to show John with his fist raised to knock again on the door.
"I heard you get up. You were a while and I just wanted to see if you were okay" John fumbled out, his voice masked with the huskiness of sleep. Sherlock's face softens slightly.
"Yes I'm okay, goodnight, John." but he knows that it's a lie. He isn't okay.
Running
He was alone now. No one, not even Mycroft was there for him now. He had to do this for John he reasoned with himself, if he hadn't done this John would be dead, he thinks and he decides that this is a good reason to go on. But, however, this reason doesn't get rid of the already imposing darkness and the loss of will.
His feet hit the ground at random intervals, almost gliding across the ground effortlessly but Sherlock knew that the ground was sticking into his bare soles and making them bleed. It was like an analogy for himself really, from the outside he looked graceful, effortless and pristine but on the inside he knew he was broken and bleeding and just waiting for the end of this endless chase. He kept on for John, he knew that if he ever stopped then John's heart would stop at the same time so he kept on going. He swore to himself that he would never let that happen to John -his John- and if he had to die (for real) to ensure John's safety then so be it.
He would have liked to be optimistic in these times but he found himself just being realistic if not pessimistic. He had been gone for 6 months now, give or take - he had no use for time now, other than counting down to when he could go home, to John- and he would most likely be gone for another 6. However it was more than likely that he wouldn't be going home. He had almost had his mind set on the idea that he wouldn't arrive home alive, rather in a casket, buried and unknown but would be able to sleep peacefully in the knowledge that he had ensure John's safety.
It was with the idea of John in his mind, he kept running.
Suicide
He had been home for around 3 months after having been gone for just over 2 years and already he wanted to leave again. Sure he wouldn't give up John's safety for their friendship any day and he knew that he would just have to live with the knowledge that he had damaged things with John beyond repair, or at least that was what his mind provided in his lowest moments. He would laugh if he saw the sight, one of the world's most brilliant people reduced to this because of one man. IT didn't seem very funny to him now though.
3 Months ago he had finally returned to John after 2 long years of waiting, John's reaction was not what he had expected, the relief, yes and the anger was to be expected but the resentment, no he couldn't burn that looks of pure rage in John's eyes. He had moved back into 221B baker street but not with John, he was engaged now, to a woman called Mary, he lived with her now and long forgotten was Sherlock in Baker street. No, now Sherlock was alone. 3 months more without John was what had pushed him to this point now, with John's own gun in his lap. His eyes bore a hole into it but he couldn't move his gaze. Perhaps it would have been better if he had died like he thought he would have? He doesn't know, but he does know that anything would have been better that having seen the anger in John's eyes and he sighs, accepting his fate.
His note - his real note this time, because that's what people do isn't it? Leave a note?- crumpled in his hand tightly, his apology to his only friend. He really was a fraud. Placing the barrel to his temple he remove the safety and hears the click. He shuts his eyes, tears spilling, the lids screwed tight together steeling him, from what he's about to do. His finger brushed the trigger and places it there. He takes one more deep breath, inhaling deeply and then exhaling, savouring the taste of air. His finger shakes slightly and-
The gun is knocked from his hand and he finds himself pulled into a crushing hug, winding him and distracting him from the outside world and from what he had been about to do, his note still crumpled in his hand. Tears spilling harder and faster, he sobs into the body in front of him.
John had come for him finally and feels that John, too, in crying. Explaining that Lestrade had been trying to contact him for a case but he hadn't picked up his phone and that despite the fact he had become a recluse he hadn't given up his deductions and solving cases and that after an hour of trying to call that normally free man he had called John -who had originally been reluctant to face the man who had make his life hell for 2 years- and explained the situation. John soon found himself on the familiar stairs in 221B baker street and walked swiftly up the stairs and had promptly search every room and having not found him had been about to give up when he had heard a strange noise come from his previously abandoned room. John had barged into the room and had found him with a gun to his head with his finger on the trigger and he knew there were no tricks this time, no organisation to shut down, this was truly Sherlock's goodbye. So John did the only thing he thought would be acceptable at a time such as this, tackle Sherlock, knocking the gun from his hand in the process and holding him closely.
Sherlock simply handed John the piece of paper still clenched in his grasp and explained everything to John. From the scars on his knuckles to the scars on his wrists. The distorted mirrors and the endless tears. The nights spent alone with his only companions, his needle and his razor. When it all became too much and he would eat everything in the flat to subsequently empty it into the toilet and then turning it on it's head and not eating for weeks. He admitted the pain he felt when he shouldn't have felt blows from words. He explained the years he was left alone without even the hope of returning, where it wasn't a half full or half empty -for in fact there wasn't even a cup anymore for he had left it at home with John- and the running and the thoughts. The words simply spilled from his mouth, spilling the information before John and before he could realise it himself he had laid himself bare before him.
Once he was done John realise just how much was behind that porcelain face and dark curls and what truly hid behind the cold exterior. He realised that he had left Sherlock at his most vulnerable and left him to fend for himself in a world that he wasn't ready to be part of again yet. John realised that he had made his biggest mistake, leaving Sherlock, not believing in Sherlock, being too caught up in his own problems to see what was in front of him, not seeing Sherlock. And now Sherlock was paying for it and so he listened to every tale and took it in because it was his fault he was here, so near breaking point and so help him if he let it happen again. So John wept with his friend whom he had left behind - but never left his heart- and he helped him.
Sherlock knew that in this world the unique and different are left alone but, he thinks, if this is being alone he could get quite used to it. Yes, he was alone, just not quite as alone as he thought he was.