Patti,
Research thoroughly any drug prescribed for your child. My experience has been that most doctors do not understand drug side effects and because of that often make matters worse.
Please understand that I am not a doctor and what follows is nothing more than a possibility that should be addressed by a physician:
Most psychotropic drugs can cause restlessness (fancy name "Akathisia") and is usually listed under "common side effects." Degree of restlessness can range from easily tolerated to agonizing. Side effects increase with dosage. A not uncommon mistake doctors make is to compensate for side effects by increasing the dose of the drug causing the side effects.
It is possible that your son did well the first two weeks because his blood plasma levels of Abilify were not yet high enough to cause side effects.
Talk to your doctor about LESS Abilify and see what happens.
Bob