If you're not close to him eating 3 times in a row, I'd just move him now & get it over with. I don't think your family's home "agrees with him", also you're not there for the reassurance he needs.
I totally hope he turns around for you & soon- BPs can be so frustrating at times. Since they can't talk or point to what the problem is, we have to play "shrink". But it sounds like "all of the above" to me. Hang in there.