It kept me alive and helped me survive during my childhood and adolescence. These days it helps me when I'm dealing with a bad bipolar episode and I'm suicidal and depressed. It's just another unhealthy coping mechanism like eating or drinking as far as I'm concerned. I've done it off and on for most of my life so it's hard to stop when things aren't going well. I can go months or years without doing it when I'm stable but it's always there as an emergency measure I know will help for a while. I know it's not healthy but sometimes it's hard just to stay alive so I figure I'll use whatever tools I can.