Have you ever taken him for a complete evaluation? I don't think he doesn't learn because he has "too much going on." Many kids have much more going on. He may have some learning problems or other disorders that are making it hard for the little guy to both behave and to learn. in my opinion he needs interventions at school. If he is at a private school though they don't have to do it. Public schools do.
Do you live with your family? If so, although I'm sure they are VERY nice, I would stop listening to their opinion of w hat is wrong and take him for testing and help by experts.
Keep us posted 
