Hi Mike,
I have some of the same symptoms as you. I am on methimazole and my TSH is getting better and my Free T4 is in the normal range, but my TSI antibodies was over 800. I too have insomnia. Either I fall asleep quickly and wake up anxious in the middle of the night or I can’t get deep sleep.
I also have migraines from the heat. I make sure to drink lots of water and stay in air condition when it gets really bad. For the insomnia, I know doing tai chi and meditation helps if I do it for at least half an hour a day. I read in one of the posts and in a thyroid book that anxiety can be an enduring symptom of hyperthyroidism. I’m hoping it will go away though. Before this, I slept 8 hours a day.