My son has been on ADD meds since the 4th grade and is now in 10th. You wouldn't believe the difference. Don't worry, it doesn't change their personality, just lets them stay focused more. My son's grades went up immediately.
Please have your Dr. recommend someone you can take him to so that you can have him tested to be sure this is what he needs. Also a real thorough physical will help rule out other things.
Prayers and hugs being sent to you...