@Anonymous: What would happen if you just walked away when he acts like this? I don't think it is worth you getting hurt - at some point he does need to take control of his own mental issues. It sounds like he is acting violent as a misguided reaction to interactions with you, so what if you just left the house and came back in an hour? He obviously needs help, but I don't necessarily know that you intervening is going to help.
If you are really committed to him, once he gets a therapist, you should probably see if you can do a few couples sessions to see what his therapist thinks your role should be in these episodes.