Suddenly Hyperthyroid again

[T808]

I had RAI in 2000 when I was severely hyper. I was put on 150mcgs and did well on that dose with no issues for 20 years. Went gluten free a few years ago. All of a sudden became severely hyper again with a TSH of 0.002 So they lowered me to 137mcgs. Still hyper with 0.09. During that time I had panic attacks for the first time in my life. Felt insane. Couldn't sleep not even for an hour. Blood pressure was 160/106 Lost 30lbs in 2 months before they figured out I was hyper again. For a month and a half they kept saying I just had anxiety and threw antidepressants at me (which I only took 2 days of). Only until I rapidly lost weight did they take me serious. They just put me on 100mcgs but I feel slightly cold now. I'm just 1 week into that. My heart racing from being hyper still hasn't balanced out yet but it's getting better. Still races when I stand or stand still. Has anyone ever heard of such a random drastic change in doses needed all of a sudden? When will my heart calm down? All replies appreciate. It's been a hard 2 months and haven't been able to work. I don't drink alcohol or Smoke