Do you mean that you took the radioactive iodine pill years ago, and your thyroid was ablated?
sometimes hypothyroidism is caused by not enough iodine in one's system.
i take iodoral each day -- 1 - 12.5 mg tablet when i get up -- and another half a pill later during the day. i also eat seaweed -- to make sure there is enough iodine in my system each day.
hope that helps