Self-destructive Tendencies

I had a semi-mental breakdown today, those are always fun. I really really really absolutely HATE crying, but once in a while the world has other plans for me. And yeah, this is personal, but I'm going to post it anyways, because maybe, just maybe someone out there sometimes feels like I do.
So I was sitting in a park crying, and wrote this. The following is completely as I wrote it in my time of weakness:

Why can't I just let go?
Why can't I forget?
Why does the past haunt me?
There's so many things I wish I could just block out, but my mind dwells on them. It's like my sub conscience enjoys torturing me.
So much good has happened in my life, why can't I think about that? Why don't the happy thoughts cross my mind when I try and sleep? What is it inside of me that forces me to see all the bad, that makes my life so much harder, that breaks me down just when I think I'm getting stronger? I can see myself, I'm aware of the self destructive tendencies, but I can't stop it.

What do you do when you can't control your own personality?

I bitch and complain about things I know aren't true, things that are unimportant. I want to stop making issues that aren't there, but it's like I feel this need to be broken, to be troubled and unhappy. To fight everything all the time. But what am I fighting for? I have love, I have freedom, I have the ability to do what I want. Until my mind gets in the picture. Sometimes I feel so strong and smart, but other times I'm completely weak, and I don't even see the point in life.

There is so much beauty in the world. The wind itself holds a thousand words. When I was little I used to sit and watch the spirits of the trees dance. But they don't dance anymore. They don't even move. I can feel good, strong life all around me, but in my mind the anger rises, always waiting to take control. I lash out at those I care the most about, including myself.

All I want to do is let go.