I was with someone who sounds a bit like what you’re describing. Upsetting the neighbours with a destructive ruckus and screaming and making all kinds of threats to hurt himself and all that. I kept hanging on hoping he’d change as he’d been quite nice when I first met him. I also kept thinking about how leaving him would hurt his feelings for goodness sakes, I can’t believe I used to think like that. I wish I could go back in time and have a word with myself.
It took me two years to leave and my biggest regret is not leaving sooner.