It's been a year, and John's coping.
He eats and he sleeps and he goes to his therapist ignores the words that he knows she's writing in that notebook (psychosomatic and debilitating grief and depressive episodes). He makes it back to the dark, moldy studio that he's rented (far, faraway from Baker Street). He keeps his service weapon tucked away inside a locked drawer, where it can't catch his eye on the lowest of days.
Mrs Hudson visits him, sometimes, bringing groceries and making tea, telling him how a school took the lab equipment, but there's still the books(and the couch, and the experiments, and the skull), and wouldn't John rather like to keep some of it? ("No, Mrs Hudson, I just - I can't.")
He went to the pub with Lestrade, once. They'd stumbled back to Greg's apartment, and he'd fucked John against the threadbare couch, both of them sloppy and desperate. They didn't talk about that, but Greg still sent periodic texts ("Are u ok? call me anytime" and "Merry Xmas John - GL") that were methodologically deleted.
But mostly, there's silence. John can't even watch daytime TV anymore, not without the loud, obnoxious commentary that he'd grown to love. Every movement seems to create a barrage of noise - a cough, the scrape of his chair against the linoleum.
The sound of a new text message.
I'm not dead. Let's have dinner. -SH
John blinks, and stares, the seconds ticking over into minutes. His blood pounds in his ears (a welcome change from the silence, really). He can't even comprehend what's happening, can't transform the doubt-joy-suspicion-grief-anger-love into a coherent emotion.
But as he grabs his coat, he does notice one thing - for the first time in months, his hand isn't shaking at all.