Need help! OCD & violent ragings

I've just found this board and joined. I hope someone here can help me. My 16 year old son clearly has OCD, however I've been told that rage does not go with this so he must have something else. I'd like to know if anyone has any ideas because his ragings are extreme and very violent. My boyfriend, a former policeman, is saying with me almost around the clock because of the violence. It is almost always there and is just festering. It is totally unreasonable. My son explodes with it and quickly goes to a killing stage where he has to be physically restrained. Something doesn't sit right with him, or he images something (you touched something and contaminated it, etc), you aren't responding to his demands fast enough, and he's off the charts. He has no limits then. He's not even the same person then. He looks for things to kick and break or throw at you. He physically attacks you with no mercy, biting viciously, going for your eyes and private parts. He is very strong then. Tonight my boyfriend felt he couldn't contain him because he was so strong. In the last 2 or 3 months, he has begun using his bed as a toliet so that he does total eliminations on his bed, bowel movements as well as urination.
I have sought help and sought help without receiving any. The doctors won't even medicate him because they say it wouldn't help and he needs to be put away somewhere for life, however no place will take him. A doctor can't even admit him into an institution. I find this all totally baffling. The only thing we are told to do is to have him arrested repeatedly until they might get tired of us. We have had him arrested one time and he was sent back to me with me having to again try to find him help. He has not been on any drugs ever of any kind. I have worked with several alternative health people and no one seems to see a yeast problem or a mercury problem in him or really much problem at all with his health. This leaves me wondering what in the world is going on and what can I do? We are exhausted trying to care for him (just restrain him) and we don't want anyone to get hurt, including him. Currently I have him on a very plain diet in case I have missed any allergy. He is eating beans and vegetables over rice or pasta with ginger, garlic, and olive oil. For a drink, I give him non-caffeine herbal teas with no sweetner. I've tried him on a wide variety of supplements and some things make him worse, but nothing seems to make him better. The few very brief times when he is OK, he says he doesn't want to be this way, he can't help himself, and can't I please help him.
Does anybody here have any idea? I'll listen to anything.
Thank you for listening to me.
Adora1
PS No professional has ever come up with a diagnosis for him. They just said he's the most extreme case they've ever seen and they can't do anything to help me other than to tell me to call the police whenever he's a threat. Tweet