How can John possibly even think of getting married? Well, here is the beginning of one scenario I could imagine… I literally just wrote down my thoughts in an hour, and I may or may not continue it… I've got ideas, but I don't really write at all… Well, hope someone will read it, would love to discuss different ideas on how John gets on after The Fall!

The world was grey. Every morning, John would sit straight up in bed, his face damp and he would think he had just had a nightmare – only to realize it was a memory, that memory, and the colour would wash right out of the world.

He walked without feeling the street beneath him, the sounds of the events around was as if under water. He looked past people who spoke to him, always looking slightly into the distance, as there was only one person he wanted to look in the eye, only one voice he wanted to hear. But that was over now. He was gone. Dead.

It had been a year now. A year, and nothing had changed. He was not back. Anything else than that didn't matter. All John could sense was the endless question in his mind "Is Sherlock here?" and every day he was crushed by the answer sounding "no".

Things around John changed. Even though the changes involved him, it never really had anything to do with him. He stopped going to his therapist. Even as sympathetic and educated a therapist she was, he saw it: He saw that she was growing impatient with him. Saw that she didn't understand. She offered clever explanations for his long lasting grief: Sherlock had taken away his PTSD, and now that he was gone, under such traumatic circumstances (she couldn't even begin to imagine, John thought), the PTSD was back in full force. She didn't understand. This was different. This was worse. This was not a disorder. This was dying, slowly, painfully, discreetly.
He had also gotten a job. Part of a small doctor's practice of three doctors. He couldn't even remember the others' first names. He only did the mundane tasks. He couldn't think anymore. Only did routines. Volunteered to do the practice's paperwork. Made up for his declining doctors' skills, earning his small pay check. Most importantly, it allowed him to do something, keep routine and avoid other people.
He had quickly learned that you couldn't go around mirroring the pure despair and hollowness within you. You couldn't scream out the pangs of pain that went through you with every breath, every heartbeat. It frightened people. It made things difficult. So he wrapped himself in a layer of nothingness, and put together a routine. It was easy. People are simple. Feeling nothing, he could see it all from above. How people expect you to interact, what is the bare minimum of human contact you must have, for no one to notice that you no longer exist.

So he went on with his routines, hiding behind his façade, knowing nothing would ever happen again.
Until something did.
It appeared to be another day, as any other day had been since.
John was sitting at the front desk. It was a slow day, and to avoid thinking, sinking, he was checking old paperwork. A woman came into the practice. She wasn't ill, but lost, apparently. "Sorry to inconvenience you, but could you tell me the way to…" She looked at a note in her hand "…31A Tailor Street?"
"Yes" John answered automatically. He knew that address. It was the address of his therapist. "It is just to the left out on this road, then right at the small street, and then right and left shortly after", he answered in his distant voice. The woman smiled. At first John didn't recognize the grimace, as it was so unfamiliar to him, and it seemed it was not a common face for her either. "Doesn't sound like I will find it. Perhaps you are not too busy… ?" It took John a few seconds to process. He was so unaccustomed with unexpected interactions. Then he realized, she was asking for his help. And he used to be a gentleman. Was there still some left of that man? "I'll take you there" he said and got up.
They walked in silence. John didn't even notice that she studied him, inquiringly, formed an opinion of him.
"This is the place" he said when they stood in the door which he had avoided for the past many months. "Thank you." She said, and stuck her hand out. "I'm Mary". "John", he answered and took her hand. She held on to it, and looked him directly in the eyes. "You are broken too, aren't you?" He looked at her, and saw her for the first time. She was pretty, strawberry blonde hair, though a few greys were working their way from her left temple. She wore a warm coat, though it wasn't particularly cold. She was about John's height, with petite features. But what he noticed the most, was that she was a mirror of himself. Dark circles under her eyes revealed she wasn't sleeping through the nights. Though laughter lines by her eyes and mouth witnessed of happier times, a full life, the grey colour of her cheeks showed her life had no joy, and the blank look in her eyes told him that she was alone: She had been left. "I am widow", she said, as if answering his unasked question. "I am…" he hesitated. How could he explain? "I had a friend…" he started. "He was… part of me. He died. He left me. And now…" he was unable to finish, words he had avoided, put away and locked in, where suddenly spilling over to a complete stranger. She looked at him: "Now you are only half of who you were". Their eyes locked. He couldn't remember when he had last had eye contact with anyone, but looking into her eyes, he heard what he needed: She understood.
He also saw something else. She was determined. She was a survivor. A broken survivor, but a survivor none the less. She reminded him of the one person he could think about.
"So we are two halves. Maybe we can split a dinner sometime then?"