He was so fucking alone. The war took every single thing he held close to his heart and ripped it away from him. He was the only survivor, the boy-who-lived-again. There was no escaping from it, even in sleep. The eyes of his friends haunted him. Her eyes haunted him. Their last moments played over in his head on a constant loop, and the memory of the life leaving her eyes was branded on his mind.
It does not do to dwell on dreams and forget to live, remember that. A very wise man had once spoken those words to him, but that man was dead now. Everyone was dead now, everyone except him. Dreams were all that remained. He lived in what could have been. This mirror had become his ritual, his addiction.
First came the deep breaths, wheezing in and shuddering out no matter how hard he tried to stay under control. He always thought that he could hold the tears and the rage at bay if he just kept breathing. He was always wrong. Seeing them all again was too much, but it was never enough either. He could feel their eyes on him, the victims of the war, and even though they smiled, he recognized their silent judgment. They had all lost so much. So many young couples, young parents, young children, and he would never forgive himself for any of them.
The uncontrollable shaking always followed shortly. His hands would claw desperately at the flawless marble floor, but they never found any purchase. He never noticed when he started clawing at himself instead of the cold stone. He had gone numb long ago. As the spasms rocked his body, he prayed – sometimes for hope, sometimes for blindness, but always for an end.
After a few hours, he would exhaust his minuscule store of energy. He usually woke in a puddle of his own blood and sweat. Old scars, new scars – he could hardly tell the difference anymore, and he didn't care. It all bled the same. Coming in and out of consciousness, he would find himself wondering if the stain would ever leave the floor. He hoped not.
This obsession would kill him someday, someday soon. Voldemort may have died, but he had taken Harry with him that day. All that remained was a husk, seemingly whole but completely hollow inside. He was done, and he knew it. He could never repent for what he had done, and for what he didn't do. The mirror would kill him, and he couldn't wait.