Abusive behavior

How should you go about leaving or taking a break with someone that hurts you. He says that he will kill himself if I leave him, he has no friends or family here to have his back after so I believe that he will. He promises me over a year ago he wouldn’t do it again and now it’s a lot worse, I feel that we Atleast need a break before something worse happens even tho I don’t think I would actually get really hurt, but I want to go about this the right way