Dear R.C.,
Definitely seek help for your son. I think it would be a mistake to regard this behavior as a normal development for his age, or to hope that the passage of time alone will be sufficient.
In most areas there are provisions for mental health care for children who are not covered by conventional private insurance. Check with your local city or municipal agencies, child guidance clinics, mental health centers, general hospitals, state child services agencies, etc. Also, ask your pediatrician or other health care professionals for some guidance re: referral to mental health services.