Continue the counseling for your son. If he needs more time than the school counselor is able to give, the school counselor or your pediatrician can refer you to a therapist in your community.
Talk with the teacher about working out a positive reward system for your son. Ask her to send you a daily note (could be as simple as a check mark or smiley face) to let you know how your son's day was, then follow up at home. A good day can earn a walk around the block just with you or an extra bedtime story; two or three good days in a week can earn having a friend over to play on the weekend. You can increase the amount of time required to earn a reward as your son's work improves.