Graves’ relation to stress is pretty well documented, the thinking being that stress and anxiety can trigger it. Those things certainly do not go away after you have been told you have an autoimmune disease with risks of thyroid storm, debilitating eye disease, etc.! Dizziness, tachycardia, fatigue, visual disturbances, can all be anxiety related. PTU, like methimazole, is a drug, not a hormone, and as such does have side effects, including muscle issues, but if your heart etc, check out okay and you are euthyroid, I would not rule out anxiety. Personally, I am euthyroid on levothyroxine and I feel normal as my TSH remains steady and normal. I did not feel great on methimazole due to the erratic hormone output of my diseased thyroid. If your TSH is too low to measure, you may have some day to day variation in your FT4. I do not even test FT4 as in my case it does not correlate at all with TSH and I could never dose hormone replacement using it. During my extended course of the eye disease, I certainly experienced anxiety. Do see an ophthalmologist even if your eyes seem okay so you have a baseline for comparison should changes occur later.