Thanks, all. No luck getting him to a doctor, but his mom is taking him to a Buddhist monk or something today. (Some of this stuff I think is coming from his parents..) I do have places to go if his behavior escalates, and I have my own money now. And friends in the police department.
I did read something about stress causing B vitamin deficiencies, but yeah, this may be more than a few pills and better food can fix.
I'm really glad to hear that you have some safety net features set into place -- your own money, friends who can help, somewhere to go. These will be vital until whatever's going on with your man can be resolved, which I desperately hope for you both that they can.
I believe my ex had a problem along the same lines. I even think I myself have something like this going on -- although I'm also entering menopause and it's hard to tell anymore the difference between hormonal fluctuation, sleep deprivation (which I chronically have), bad nutrition or plain old going crazy/psychotic, lol. I may be all these things, hah.
But I suspect that my ex was too. (Well except for menopause.)
He displayed unreasonable behavior -- we once had a terrible fight in which he was screaming "Stop shouting at me!" over and over....when, for once!, this time I had actually been talking deliberately quietly and kindly in an effort NOT to let it become an argument....When someone thinks you are shouting and screaming when in fact you were being gentle and almost whispering, there is clearly something going very wrong with their perception. This and other things made me see that he was having problems mentally that even he didn't seem to realize.
I had to get out under unprepared circumstances and it was hell -- I'm relieved that you are ready to take action if things escalate unexpectedly before your partner can get help. Please try to get him to see someone. Mental illness is so hard to separate from common-or-garden jerk-ness, and it is poorly understood or given compassion for, by both the sufferer and the people around them.
If my ex had faced up to possibly having these problems we might have been able to stay together and work through them, and the same goes for me, if he had seen perhaps I'm also having problems along these lines, and to hang in there for me. But nope.
Please get him help somehow someway so that you guys don't have to go the worst "place" in all this; I wish you the very best in everything; hang in there.