This is NO slash. Actually this is Johnlock but unrequited love/one sided love on sherlock's side..
So this story is about the Holmes brothers and their difficult relationship.

What brothers are for

I didn't know where I was, but my head was hurting – badly.
Not only my head but also my left arm was in pain.
My whole body was aching. It felt like I was burning alive.
The pounding in my head got worse.
Shouldn't have opened my eyes...
I couldn't remember what happened last night.
I looked around and recognized my bedroom.
Then I saw the needle and the empty cocaine bottle on the floor - all the memories came crashing down on me.

John was married. I was attending his wedding yesterday. He was married to this horrible woman.
My unrequited love
lost forever
out of my reach
He left me.
I was all alone - again...
I felt sick.
My body was sore, and my heart was breaking.
My eyes were burning and without actually realizing tears were running down my flushing cheeks.
I wished I would have overdosed last night. Then I wouldn't have to feel this agony of self loathing hatred. Oh God help me, how I abhor feelings, emotions... necessities which I would love to simply turn off. How hateful, my mind rebels at the thought of giving in to those simple human needs of affection. But John changed me; he weakened my mind and my heart.

I wiped the tears away and forced myself to concentrate.
Desperately I started looking for my mobile.
After looking for it for a while, still feeling delirious and weak on my feet I was able to find it under my pillow. I unlocked it and saw '13 missed calls' and '20 new messages' ... well probably from Mycroft.
Mycroft... tears came to my eyes again. I suddenly felt the need to call my brother.
Twice it was ringing then he finally picked up the phone. ''Sherlock?'' his voice was clear but he also sounded a bit alarmed. Well I practically never called him.
With my hand I wiped the constantly and apparently never ending flow of tears away, they just kept coming. I had to sniff.
''Sherlock? What's wrong? Where are you?'' His voice louder now, worried.
''Mycroft? Please come... I... I'm in my flat.''
''I'm on my way.''
The line went dead. I knew that he would be here in about fifteen minutes.
I sat there, on the hard floor of my bedroom and curled myself in a foetal position. Waiting. Waiting for my brother to come and put me back together.
I lost all feeling of time while I was laying there. I didn't even hear the door open. Mycroft was practically storming into my flat. MY flat... It wasn't John's and my flat anymore... just my flat. I was so alone.
''Sherlock?'' I heard Mycroft call for me.
I only whimpered. He must have heard because only seconds later he was standing in the door to my bedroom. He looked down at me and I looked in his dark brown eyes.
In this moment I lost all composure.
I started crying and wanted to hide my face in my hands but I felt my brother moving closer and with one fluid movement he pulled me in his arms and against his torso.
I felt too weak to protest and sobbed desperately against his chest.
''Oh my dearest brother...'' his voice sounded so deep, full of affection and sad.
I have never heard him speak to me like that.
''He... he is married.'' I choked out.
''I know... I know.'' He whispered.
We sat there probably for hours, on the hard floor of my bedroom. Mycroft simply held my in his arms and stroked my head or my back. He didn't even mention the empty cocaine bottle or the needle on the floor... he kept quiet to my obvious drug abuse from last night.
He just held me in his arms and let me cry my broken heart out.
''I knew you loved him. I'm so sorry Sherlock. I know we have a difficult relationship but you ARE very dear to me brother, and I would never wish any harm to you. All I wish for is your happiness and that you are well. As I once said; I worry about you... constantly. I love you brother.''
I was listening to him and his words gave me a strange kind of comfort.
I shook and shivered against him.
''We have pulled through rough times before; we will make it this time as well. I'm always there for you.''
The tranquillity left me once more and a new wave of tears overcame me. I couldn't stop it.
My body shook and trembled. I almost hyperventilated and hysterically I cried against my brothers' chest. My own chest was hurting badly it felt like someone had ripped my heart out, and my eyes were burning. I felt blinded by the tears I shed.
It was humiliating.
''I'm a man sworn to logic... I don't need those stupid feelings... and I don't need John. '' for a moment I tried to catch my breath. ''Make it stop hurting... Oh God! That bloody awful woman!''
Every sense of logical thinking had left me long ago.
''We will hate her together.'' I heard Mycroft whisper against the top of my head.

After a while I calmed down a bit and slowly pulled away from my brothers tear soaked shirt.
''Thank you, brother. Sorry for that.'' With the last part I was referring to his shirt.
''Never mind that. That's what brothers are for.'' He looked at me with a sad smile and it also implied a question. A question he didn't had to ask. ''I'll be alright. I just need some time... I guess.''
''Would you like to get away from here for a bit?''
''Where to?''
''Wherever you want to go.''
There was a short silence between us. I was thinking about his offer. It seemed reasonably to me. Getting away from here would be a good thing. Getting my head clear.
''Scotland?''
He smiled at me.
''Sure.''
I fell silent again. There was something on my mind. A question I didn't dare to ask him.
But Mycroft being my always observing and always-worried-about-me brother knew that I had something on my mind.
''Sherlock?''
I looked at my hands which were folded on my lap. Slowly I looked back up into his eyes.
''Would you come with me? I don't really feel like being alone...'' My gaze drifted to the needle. His eyes followed mine.
''If you want me to come with you, I will.'' he took my shaking hand in his.
''Thank you Mycroft.''
''That's what I'm here for. Always, my dearest brother.'' I was not used to such kind words spoken by my brother. But right now I thought that they were soothing, calming and his voice was gentle, deep and quiet.

It was true. He was always there... never far away.
We may have a difficult relationship but he was always there for me.
He always accepted me the way I was. I guess he was right. That's what brothers are for. I leaned my head against his shoulder and closed my eyes. We sat there, just the two of us. His company gave me some strange kind of serenity.
My eyes were still burning and the sadness over a broken heart was still lingering over my being like a dark shadow. But I understood that at least my brother would never leave me.

And that was enough for me.