I tear the skin around my fingers and I can't stop myself from doing it.
That sounds like it hurts. Can you tell me why you do this?
Because I'm a bad person and I hate myself and want to punish and destroy myself
You are inflicting harm upon yourself and this behavior is a serious mental disorder. Get some help from a qualified therapist or this could escalate into something more serious.
Nah, I'll stop when I'm tired of it.
I don't think you are in the right mind and can't see how destructive this behavior can be. Self harm can spiral out of control and turn into something worse. You should find better coping skills.