The World Would Be Better without Two of Us

I’ve been hurt enough times by this man, the world would be genuinely better off without him. He hurts everybody else around him, they’re a cheater, a liar, an abuser, a genuine sociopath. Somebody that welcomes the pain that they cause.
I need to go to the psych ward or something for these tendencies because I find myself staring at him, just planning… but I can’t afford it. Let’s say that these feelings pass over eventually without the help, but what if they don’t? I generally have pretty good self control, but I have Disruptive Mood Disregulaton Disorder as well… aka, when I get upset, I go fucking insane.
I forced him to leave the place for a few days because I’m genuinely scared of what I’ll do, because I really don’t have thaaat much to lose. I’ll just kill myself afterwards, but how do i get rid of this rage? I don’t want to actually hurt anyone, my emotions just get so intense and I get trapped in this pattern of thinking that the world would genuinely be a better place without both of us. I’m scared.