This was written because of that look in THoB I don't really know what to do with it so I'll just leave it here...
Sherlock sat staring at John. He was sorry, he hadn't known John would be angry at him for the experiment. He'd thought John would help willingly like he did in everything else. Sherlock's chest suddenly felt constricted and it actually hurt.
Now, even if he pretended he didn't have emotions he knew what that was. He knew. He'd had this feeling looking at John and being with John for months now, there was no use denying it. John didn't know, and he doubted John would ever know if he himself didn't tell him. He felt a sudden pining, an urge to kiss John, to hold him close and make everything better between them.
Emotions made people irrational, Sherlock knew that, and he'd been so much more irrational than usual on this case. Fear and doubt had clouded his thoughts in deducing and he'd been even more irrational still lashing out and taking it out on John. He knew he'd hurt him, he could see it and he was sorry, so very very sorry. Sorry for everything. Sorry for insulting him, sorry for lashing out, sorry for using him in his experiment, sorry for never letting him in.
Sherlock had never had anyone so close to him emotionally before, and however much he didn't want to admit it, it scared him. Scared him to let anyone past his walls, let anyone so close to his heart. John was already too close, he cared about him too much. If he let John any closer he gave John the power to break him irrevicably and that terrified Sherlock. He didn't need drugs to feel fear or love or anything else of that matter, he just tried to set them aside in perferance of logic and rationality.
But John, dear John, affected him in ways he couldn't comprehend, he could only guess at the cause. Sherlock loved John Watson. But why did Sherlock feel this way about John?
As Sherlock sat there pining he couldn't help it, it just slipped out.
"John, I think I love you."
John didn't even look up from his meal as he shook his head slightly and Sherlock was breaking even though he didn't think John even understood he'd meant what he'd said. Sherlock wished John would just look at him, look at him and see the heart wrenching pain he was in, just understand for once that he actually felt something... that he was telling the truth. Sherlock knew he loved John, he just knew. Maybe he was even in love with him. But he couldn't know what John was thinking, couldn't even know if John had heard him and he needed to know. Sherlock needed to know what John was thinking now. What John thought about him.