I think I have problems..?

Well, I'm kinda bored with life tbh. Nothing really excites me anymore. Overall, im happy, a lot more happy then i used to be. And I'm happy with who I am too. The other day I went on a day out with my friend, it should have been fun but I was in a down mood the whole time. I was bored, i felt totally empty. I was all like 'is this it.' I've been feeling, generally, happy and content these past few months, i get on with my parents now, i am more confident, i have lots of good day, i know who my friends are. It was the first time i'd felt like that in a long time. So it kinda scared me. I didn't wanna go downhill from there after everything:/ But now, after -what? three months?- of being happy (sort of) and having nothing particularly bad happen in my life, i'm started to feel empty and bored of life. It's like with everyday I feel empty and bored, I die a little inside (a bit dramatic but that's how i'd describe it). And then I'll have a good day or two, and there I pick up where I left off with the boredom thing. I've started to bruise myself too. I've started getting into fights, simply because I love getting punched, scratched, bitten, i love to vent my anger on others, i love the rush. I completely hide my feelings, i never cry and i'm kind of bitter and sarcastic. Complete opposite of who I was. I feel bored, I'm starting to become kind of evil, I obsess over things, I don't really know who I am or who I want to be, and the bad days are creeping back in. I don't think im particularly ugly, not anymore. I know i can be a good friend, I can make people laugh, I'm smart. But I'm now unpredictable, even I don't know what I'm gonna do next. I'm bored of being nice aswell. Technically everything IS going right. But the self harm? Random feelings of complete boredom? Kind of becoming a bad person? Obsessions? I think I need help..:L