Did you try having just a quiet time? Instead of nap time? Like if you don't co sleep or even if you do. Tell him it's relax time or quiet time time for a book or some classical
Music and make it an hr long. Maybe he will fall asleep maybe not but at least you get a little time to relax. If you don't co sleep put him in his crib or bed for an hr or on the couch with you or something