Some wonderful suggestions here. I have to agree that this sounds like it could be an attention-getting tactic. We want so much to help our children succeed, as much for themselves as for our convenience, and yet our efforts often to the opposite affect: our child gets far more of our time and engagement than they do just using the toilet.
If it were me, I'd consider how to reverse those dynamics. I wouldn't 'reward' using the toilet, but try to find other ways of giving your son some little pockets of special attention unrelated to the potty issue. Then, when he does wet or mess himself, offer him some time in the bathroom to change himself (bring in a plastic bag and clean clothes) and see what you can do to be otherwise engaged for five minutes or so. "I'm right in the middle of (dishes, laundry, etc.), but work on it yourself for a bit and then I'll come help you when I'm finished." (This may not work for poopy pants, but those happen less often.) Taking a break does two things: allows you to emotionally disengage regarding an issue that is obviously vexing after a while and sends a message to your son that #1-you think he's capable of taking care of this little task and #2-doesn't immediately provide the payoff, which is attention from you.
It's difficult when a child's intrinsic motivation points them in a different direction (attention instead of proficiency in toilet learning) but granted all the changes that have come up, expect that this may be a longer process. The more you can send positive signals to him that you love him and that toilet learning is HIS challenge, not yours (and that you will be patient with it) he'll be encouraged to move forward, even slowly. And having social opportunities to see other children his age using the toilet might be just what he needs. He'll get it eventually!