What should I do?

Long story short I love my SO deeply and despite he would say otherwise, I don't think I'm very good for him. I am a stressed out ball of blind anger, I'll have mental break downs and episodes and I know it has to take a toll on him. Should I let him go in hopes he can find someone healthier and better for him? We're like best friends, but I've hurt and chased off so many guys in my life and I'm so scared I'll do the same to him.