V.M.
I would talk to his pediatrician about this and maybe even see a child psychologist. It is effecting his relationships with family and peers, so I think you should seek help for him somewhere. Is your son developing normally every way else for his age? If you have other concerns with this too, you can check with your local school district and have him tested for development. Please don't wait to help your child, if something developmentally is going on, now is the time to take action. I wish you luck!
Take care.
V.