My boyfriend is hurting me

I been thinking about suicide for 2 years now, and I think im about to reach my limit of how much more I can take, I met a guy and when I’m with him he makes me happy, but when he’s mad he yells at me and a hurts me inside when he does, I always forgive him because I’m in love with him to much. He also thinks about suicide and/or running away, he says he’s gonna cut himself when he gets really depressed and I always manage to stop him before he does, but then I’m never able to worry about me, I dont cut myself, I used to scrape myself and even now I burn myself by taking a lighter and a peice of metal and heating up to metal and putting it up to my arm. I hate that I do this and i’ve tried to stop, but I never can. I even told my boyfriend that im suicidal and he said if I kill myself he will too, and I told him the same thing. If he dies then I want to die with him. But that also scares me, I cant stand the thought of losing him and now I worry about him a lot, I always want to know if he’s safe and breathing, Its tearing me apart to have to live like this every day but I dont want to leave him, I never ever want to leave him. I’ll do anything to keep him alive and here. Please…someone help…I can’t do this anymore!