I self-harm. I started with just scratching myself with the intent of causing pain, to punish myself when I felt I'd done something wrong, and it's progressed from there - eventually I wouldn't be satisfied until I saw blood, and then until I saw enough blood. I think I first started the scratching sometime in high school, and didn't progress to cutting until sometime last year. Nowadays, it makes me feel better when I'm really upset. For some reason (can't really explain it), I really enjoy the sight of my own blood, and enduring physical pain makes me feel strong, tough, when the emotional pain is getting too much. I will usually start because I'm upset, but keep doing it for longer than I might otherwise have because it kind of becomes a stim - like, maybe one flow of blood from a cut would be enough, but I'll keep scratching at it to make it bleed more as a stim.
_________________
Yet in my new wildness and freedom I almost welcome the bitterness of alienage. For although nepenthe has calmed me, I know always that I am an outsider; a stranger in this century and among those who are still men.
-H. P. Lovecraft, "The Outsider"