You have a very tough problem. Like the poster above, I would suggest you connect with experts in the field of domestic abuse.

You seem to be very focused on his psychiatric diagnoses. Not all people who have schizophrenia or severe mood problems are violent. Your boyfriend is violent. That is the problem. Do you have any contact with the doctors who treat him? When he is not staying on the property where you live, where does he stay?

It sounds like you need to keep him off your property, but that can be tricky to accomplish. You may be confusing him with mixed signals, by staying involved with him. You might want to think about getting a guard dog. See if your local police have any special services for victims of domestic violence. They should have some advice for you. This is a dangerous situation you are in, as you don't need me to tell you.