My girlfriend attempts suicide when I try braking up
It's been a while since I've tried to brake up with my girlfriend. I can't never actually achieve it because she sort of threatens me that she will kill herself because she can't live without me. So this past time I tried braking up thinking she really wouldn't do anything, she did. She cut her wrist and was bleeding. It truly freaked me out, especially knowing she has heart problems. As a result, I went back with her.
My reason for trying to brake up with her is because she cheated on me a while ago with a 13 year old (she's 19) and lately everything has been arguments after arguments. I've become extremely jealous, and I simply need my space.
I don't want her to do anything to herself, but I don't want to be with her either. What do I do?