If in fact his sponser said what your bf said he said, his sponser must be one brick short of a full load. Did you actually hear the sponser say this? Or is this another lie from Mr. Wrong? Live together to work this out? Surely they jest.
As for your son, he is a child, as an adult you need to make the right decisions for him. Don't confuse religion and common sense, they do not mix.
Please stay where you are, there is no reason to move in together, none. You have your own house, keep it, he wants you to become his prisoner, so that you have no options, no where to go. It is all a game to him, once he gets what he wants, all hell will break loose.
Listen to your therapist, if I were you, I'd go to one on my own, without him.
There is no hurry to do anything with this guy, I would advise no contact, back off for awhile, what's the rush?