Sherlock paces the room in the flat that's not Baker Street. He plasters on three nicotine patches to relieve himself of the pain throbbing in his mind, his body, his heart. He looks outside, the city bustling about without a care about the turmoil going on inside Sherlock. This is why he avoided people, this is why he never understood people. How does one deal with the pain? Because no matter what people leave you, or you leave them. Life happens just like it did with Sherlock and John, and even fake death happens. When people care they do things for others. When people care they jump off of buildings for them. When people care they endure torture. When people care they hide out in a flat and never tell them they are there. Sherlock, for the first time in his life truly cares and it confuses him.
How was he supposed to tell John that he was alive? Should he show up at his door and smile? Should he send him a text message like the old times? Should he call him? Should he asks someone else to do it? Should he write him a letter explaining himself? Should he just jump off of that building for real and be done with it?
There is no bloody manual for this. Not that he knows of at least.
This was one of the reasons why Sherlock needs John. To tell him how to do life. John knew, Sherlock was clueless.
He isn't sure why his heart races. Is it the anxiety of not knowing? His whole life Sherlock knew everything whilst others didn't. Is it the anxiety of seeing John again, close up? It has been too long. The longer he doesn't see him, the longer the image he has in his mind is distorted. Of course, deep down even Sherlock knows that it's the fear. The fear of rejection. His whole life he's been rejected by people because he was different. But then John jumped into his life and shook the universe up. Sherlock secretly clamoured for John's appreciation, his veiled adoration, he wanted John to accept him and he had. But now...after what happened...Sherlock knew that it wouldn't be easy. If Lestrade and Mrs. Hudson reacted the way they had he feared how John would. He didn't care to be accepted by people. He cared to be accepted by John.
Sherlock spends the rest of the day figuring out a way to tell John, to make him understand.