A/N okay its 1 am and this popped into my head so here it is. It's probably got a ton of grammar mistakes but I'm half asleep so bear with me here
"Dammit" John muttered, "Sherlock! I can't carry all six bags up, get your lazy arse down here and help me!". It was no use and John knew it. The detective was most likely busy setting fire to the kitchen or watching mold grow in their pans. Him and his bloody experiments, John thought bitterly as he trudged up the stairs into his flat.
"Sherlock, I got your damned milk and those vanilla biscuits you like. And there better not be a head in the fridge, I swear, I can't deal with tha-" Sherlock was sitting in his chair, eyes closed and completely still, with a letter crunched in his hand. Something about the combined stillness and silence of the detective made the doctor uneasy and he stopped talking abruptly at the sight of it.
"Sherlock? Sherlock what's wrong, what's happened?" John asked, his voice tense and anxious as he prepared for the worst. When he failed to answer, John slowly made his way towards Sherlock, his hand slightly reached out as if he was about to place it on his friends back when Sherlock's eyes suddenly snapped open, looking into Johns. The intensity of emotions his eyes so rarely held startled John. There was anger and confusion, but above all, there was despair in his friends eyes.
"She's dead, John." He spoke so softly that John nearly missed it. Looking closer now, John could see the faint tear streaks dried on his friends face, the slight shake of his hands and the shallow breaths that showed Sherlock had so clearly given up on forcing his body not to betray his emotions. John had never seen Sherlock like this before, and he had hoped there would never be a time when he had to see his friend in such a condition, but he knew it was inevitable and the day had come. Reaching out slowly, he took the letter out of Sherlock's tight grasp, careful not to rip it.
Dearest Sherlock,
It has been nearly 7 years since I've seen you now. I think of you every day and miss you dearly. Mycroft has told me all about your work and your new friend, Doctor Watson. Your brother has made it clear that this Doctor Watson has brought a great deal of change to your life. I sincerely wish I could have had the chance to meet him; I know he must be a good, patient man to put up with you on a daily basis. Mycroft mentioned that you haven't touched those filthy drugs, and have a more normalized sleeping and eating pattern since the good doctor entered your life. He has also mentioned that you have been working with the Scotland Yard now, doing proper detective work and finally putting your skills to good use.
Though you may not believe it, i regret not being there for you more when Mycroft and yourself were young. I hope you can understand now how difficult it was for me to take care of your brother and yourself when your father died. You were so young at the time, and without your father to teach you how to properly control your emotions, you elected to shut them out entirely and I can't help but take the blame for that. Instead of teaching you to manage your feelings as he had done with Mycroft, I taught you that emotions were useless, irrational. A disadvantage on all fronts. At the time, I believed I was doing the right thing. I know now how wrong I was for teaching you such things. I will regard this as my one true mistake in life.
Know that if you are reading this, I am dead. I've been very sick, Sherlock. I have a brain tumor, inoperable. The doctors told me two days ago that I would last another month or so before I physical and mental state began to deteriorate. I have made plans to end this life on my own terms. I refuse to sit back and let myself turn to ruins. I have lived a propitious life, and I have accepted that it is time for me to move on from this life. I am not sure what road your life will take you down, but I hope it is enthralling and adventurous.
You are a good man, Sherlock Holmes. I am so proud of you.
All my love,
Syril Vanneese Holmes
"Oh, god, Sherlock, I am so sorry. Do you need anything?" "John, I-" "Tea, coffee, maybe some biscuits, would you like that? They're your favorites Maybe do you wanna just head to Angelo's and grab something to eat? It might make you feel better." "Actually, John-" "No, sorry, no that's stupid you probably don't wanna go out right now. We could just get take-out? Would you like that? Mycroft probably got a similar letter, have you talked to him? Maybe you should call. "No, John really, don't. I just-" "Maybe I'll call him, would you want me to-"
"JOHN!" John's head snapped up, startled by the sudden uprising. Sherlock's voice was husky and quiet, so different from the usual velvet tones he so loved. He didn't realize he was still clutching the letter and handed it back to Sherlock. The detective swiftly stood, taking one step closer to John, they were only inches apart.
"John, I really just need you to help me." With one quick look up into the detectives eyes, John quickly wrapped his arms around his friend just moments before his face crumpled and he began sobbing into the doctors shoulder. John sat them both on the ground, careful not to take his arms from being securely placed around Sherlock's waist. He brought one hand up to stroke his friends hair, slowly rocking them back and forth as he whispered soothing words into the detectives ear. After laying together for what seemed like hours before, with Sherlock rolled into a ball and John acting as a protective wall cuddled against him, that Sherlock finally surrendered sleep. John cautiously grabbed the closest blanket and wrapped it around them before kissing the top of Sherlock's head and welcoming sleep as well.
The next morning, Mycroft found them sleeping together, legs and fingers entwined and decided it best to come back at a later time, silently thanking the doctor for taking care of his brother.