Hello mattsnow: I would suggest this is something you should be talking with a therapist about. From my perspective this is a symptom of some deep-seated self hatred that stems from something, presumably in your past. The only way you're likely to get past this is to figure out where it's coming from & what it's about.

The other concern I would have is that, at least from my experience, this type of thing tends to become more serious as time goes by. At one time, I used to do the kinds of things you describe in your post. I never really thought too much about it. Now I have a history of two major suicide attempts & some permanent physical problems related to more serious self-harm activities I took up as time went by. Don't do likewise. Deal with this now while it's still relatively harmless.