I'm really tired of this. I've been completely miserable with myself for years and don't know how to help myself
That sounds like a struggle. Why have you been miserable for such a long time?
I hate the way I feel all the time, I'm depressed most of the time.
Depression can be difficult to escape from by yourself. You should seek professional help if you're having difficulty getting by on a daily basis. With as much time that has passed, you deserve to feel better about yourself.
I'm not going to therapy, I think I can do it by my self and maybe I'm fine like I am.
You said you've been feeling this way for a long time. I really feel like it's time for you to get some professional help, so you can start feeling better.