I agree with the others. And once you've removed yourself from this situation, you can expect one thing- that he'll come back to you pleading,promising to change, etc. If you fall for that right away it will probably start up all over again, worse than before, because he'll know you're a pushover. And if you say no he may very well become abusive and threatening. Then you may have to get a protective order. You may need to put some geography between you and him. It's not going to get better until he realizes that it's him, not you. It's him and specifically it's that beast way down in his brain which, for the near term at least, has taken over. Until he makes up his mind that he's got to fight that beast and win his soul, his true self, back he's going to get worse. He'll make his life a living hell. You don't have to share that hell with him. And caving in to him, allowing yourself to be manipulated, can only make him worse. Will reduce his chances of recovery.
W.