This happened to me. Have been overweight my whole life imagine my shock to learn I was hyperthyroid as well. Turns out I have an autoimmune disorder called graves disease .you have to go to an endocrinologist and make sure that they're testing not only your TSH ,also free T-3's and free T4. you also want to have them run antibodies for Graves' disease or Hashimoto's disease. I'm surprised your doctor hasn't recommended putting you on anti-thyroid medication ,typically they will put you on methimazole or PTU. If you're hyperthyroid is caused by an autoimmune disorder such as Graves' disease, being on antityroid medication short-term could put the disease into remission. I was on the anti-thyroid meds for almost a year and my graves went into remission and that lasted about 10 months. But inevitably it flared back up again. At this point for me personally my doctor wanted me to undergo radioactive iodine or have a thyroidectomy. This is for several factors one being that I am planning on having another baby so they felt it is safer for you to be. Hyper thyroid and on thyroid medication to manage the disease better throughout my pregnancy.
So I had a thyroidectomy four months ago.... All this happened prior to me finding the primal lifestyle. Ask me now what I would do differently had I been armed with the right information and it would be completely different. If I was you the first thing I would do is find a good endocrinologist, have them run the test that you need To see whether this is due to autoimmune disease. Then from there based on that information if it does turn out that you have Graves' disease go on the anti-thyroid medication . If you have a good doctor they will have you run labs every 4 to 6 weeks to monitor your blood work. At this point I would follow an autoimmune protocol of primal/Paleo and I would also take care to avoid what is known as Goitrogens /cruciferous vegetables. Perhaps Being on the meds and following this diet you will find that you can get into remission. Whatever the case maybe it's not something to take lightly hyperthyroidism is way more dangerous than hypothyroidism you could have a heart attack Or suffer a thyroid storm and go into a coma, so not to scare you but definitely get yourself to an endocrinologist.