I had Thyroiditis a few years ago and would go from over-active to under-active.
Thyroiditis is caused by a virus in the thyroid. This was dx as my thyroid levels were not in the norm.
I had to have a radioactive test to check out my thyroid and all came clear so that it why it was dx as thyroiditis rather than hyper or hypo. I didnt have to stay away from my kids etc afterwards, but could see why b/f could be an issue. The dye test told be that it was a virus that caused the issues. It was either going to be a virus, graves disease or a goitter that was the culprit! As no sign of the last two- it was seen to be a virus.

Thyroiditis is a virus that attacks the thyoid. I was under a endochronoloigst for 18 months whilst i was suffering with it. Regular monitoring of levels, which fortuately didnt get bad enough to go on meds, but my levels did swing from one end of the scale, to the other.

Is it possible that your thyroid condidtion has been caused by a virus as well??
The dye test is the only way of knowing why your thyroid goes hyper or hypo unfortunately, so maybe is maintenance time until you stop b/f.

Good luck and stay well!!

odette