It’s possible you may be allergic to the anti-thyroid drug you are taking. I also know of someone who just needed her dosage lowered. I had a reaction to the first one I was on, switched, and now am pretty happy to just continue on with my current ATD, and may stay on it indefinately.
RIA and surgery are big (and irreversible) decisions. You’re right to start looking for more info. An ATD can buy you some more time if your not allergic.
Good luck and good health
Julie