OK, I suffer from the same thing he does. As far as him not wanting to take medications. Myself personally I feel that he just doesn't want to help himself. I know what its like to spiral down what he is doing. It is not something you want to deal with. Since you have been with him only 3 months. I suggest you break that tie you guys have. Yes you might like him, but I am going to just straight up tell you, if he refuses to get help no matter what anyone says or does. You will NEVER actually have a real relationship of any kind.
As far as contacting his psychologist/T So not a good idea. You think he is hostile towards you now, one of the things with the disorder he suffers from, it can make him extremely violent in the blink of an eye, if he finds out you did something like that. Because the more that the illness is untreated, if he hears voice with the disorder, they can make him turn on you so fast if he doesn't realize that the voices are just voices. you would be putting yourself in harms way.