If you took the radiation pill, it means your thyroid is dead. That also means you need to be taking thyroid meds.
Yes, thyroid meds should help get your weight under control and make you feel much bette.r
Your doctor must test your FT3 and FT4 and TSH. If your TSH is low doesn't mean you don't need thryoid meds. In such a case your FT3 and FT4 should guide your doctor to your medication dose (both should be at least middle to upper half of the reference range).
HOpe this helps.
How can you not be taking thyroid medication after RAI? Do you have other hypo symptoms besides possibly low metabolism? Take a look at this list of typical hypo symptoms and see if you recognize any that you have.
http://endocrine-system.emedtv.com/hypothyroidism/hypothyroidism-symptoms-and-signs.html
You really do need to be tested for the biologically active thyroid hormones, which are Free T3 and Free T4 (not the same as Total T3 and Total T4), along with TSH that they always test for. Many of our members report that symptom relief for them required that FT3 was adjusted to the upper part pf its range and FT4 adjusted to around the midpoint of its range,