In my view you have a MAJOR toxic condition or congested liver problem.
3. More sluggish with Iodine?
Sounds like detox symptoms. However.
Terminate the Iodine for a few days and see how you feel.
Go to one drop per day and see how you feel.
You will have detox symptoms, but I would try to stick with a low amount until the ability to regulate properly comes back on line. Keep increasing and stop go back to prior level when you start dragging.
It’s as U said, you’re attempting to kick start the thyroid, in your case you may have “flooded” it.
Learn to give yourself a break any time things get “bad”.