Help please

When i first got into the relationship with my boyfriend he seemed alot imbalanced. As days got by i noticed alot of weird actions, after a while he started getting mentally ill he was afraid that i passed hiv to him, i got tested twice and he still thought he is sick i proved to him he is not sick but still he had thoughts and tried to commit suicide, he also beat the shit out of me, then after a while he started getting obsessed over the fact that i had a relationship with a black partner.

He would think about it alot and dream about it. The sad part that he hit and abused me and yelled at me calling me bad names. Everyday i tried to leave then he would put the blame on me because i made him mentally ill because of my past. He had obsesstions that everybody hates him and alot more obsesstions. I did everything for him i helped him with university, i cooked and cleaned i was there for him in every possible way. He would always say things like im fat or just calling me names. He refused going to the doctor and i had to lie to him because he tried to commit suicide and was a danger to me after he sent me to the hospital i told him he was my first. I feel guilty but that was the key to make him feel better but he still hit me after. He confessed that he was on medications for his mental illness before he met me and he stopped it and it was all because of his illness that he was hitting me and treating me like shit. He went to the doctor and he's on meds every time i wanna break up he blames me for his illness and starts to threatens me to do bad things to me or to kill himself. I really need to move on i still have nightmares from when he used to hit me but i dont know how to break up. He wants to get married...