Him threatening to kill himself is emotional blackmail. You are being held hostage in your home because you're afraid of what it will do to his mental health. That is not fair to you whatsoever. He's responsible for the state of his mental health, not you, and you deserve to be able to break up with him as you please. It's also your right to ask him to leave. Don't allow him to stay because you're afraid - you will continue to be a hostage within the relationship. IF he threatens suicide again, tell him to call 911 or a suicide hotline. I would, if it were me, simply explain to him that the relationship is over and that you want him to move out. You can be nice through the breakup, but his life and his problems are HIS responsibility, not yours.