I think that when you're angry at yourself, it can be a sort of roadmap for you. If you want to change. But I think sometimes anger is inexplicable - it's raw and it's real and you bottle it up and then one day you just can't handle it. Everyone has issues; the trick in my opinion is learning how to forget and forgive them, especially your own issues. You just have to let go of your anger.
I also think that growing up...it's rough, dude. I dunno about you guys, but there is so much drama in my tiny high school. And that maybe sometimes you have a right to be angry about it. But you can't move on in your life holding onto anger.
Yeah, though, that's what I think. You need to examine your anger and see if it's got a tangible reason, and if it does, are you going to let yourself change? If it doesn't, can you let go of it?
er...yeah, that's it XD