What to do about BF's uncontrollable anger issue?

I have a very impatient BF which I've been living with for 5 years now. Everything is great and dandy until I have something important to discuss that he doesn't agree with. He loses his patience immediately, starts screaming at the top of his lungs and makes up his own answers to his questions for me, he riles himself up and starts to call me terrible names, demeans me and tells me I am a nut case (if I have valid concerns about anything). I won't stand for this and told him so and will not take it anymore. I suggested he get counseling for his anger issues about things that no normal person would be angry about. He refuses. I'm ready to throw him out over these once a month tyranting episodes. Any last minute suggestions before I have no other choice but to kick him out? We otherwise have a great life and great team work in everything. What's up with this guy?