If it was detox from the Bromine, you would be experiencing the opposite. Bromine has been used for its' calming effects.
I think you are stimulating your Endocrine System. I am not sure exactly how it works but you can do research.
The Thyroid and Adrenals interact with each other. This could mean a change in Cortisol Levels.
The safe upper limit is set at 3 mg in Japan and 1 mg in the USA. I think you need start at a smaller dose. The thyroid is sensitive to big abrupt changes.
Are you using Lugol's or Iodoral? That dosage is supiciously close to half of an Iodoral or two Drops.