I don't know anything about body building but is there a chance he could be on some sort of substance like steroids? He sounds very all over the place as far as his anger and emotions.
It sounds like he doesn't know what the heck he wants. I wouldn't let him back into your home unless he seems serious about saving your marriage, and agrees to some sort of counseling. The back and fourth is awful.
I suggest IC for yourself as well.
"Everyone you meet has baggage. Find someone who loves you enough to help you unpack." ¤Formerly DelinquentGurl¤