I don't wanna hurt him

My boyfriend has loved me for four years now, I didn't love him back till just a few months ago. Now that I've realized my feelings for him I couldn't imagine loving anyone else. I feel that I'll never be good enough for his love considering how many times ive turned him down. I have pretty bad Bi-Polor disorder and at times I hurt myself and I can't control it. He has to constantly worry about me while I constantly worry that I'm going to hurt him. Wether it's because I hurt myself and take it too far or that I leave him over my insecurities/wanting better for him. I just don't know What to do. We're also long distance cause I moved states about a year ago, we visit every year but it still complicates things. I don't ever wanna give up on him or us, I just don't know what would be best.