My mom seems to have this same problem with low potassium and there has to be an adrenal connection.
She uses a corticosteroid inhaler which keeps the adrenals from functioning properly.
She has no problem with 100mg of Lugol's which is only 60mg KI, but has big problems
with only 6 drops of SSKI which is 180 mg of KI.
I will try the potassium chloride 1/2 tsp 3 times per day and see if her runny nose/sneezing stops with 6 drops of sski.
OK, one more idea to add to this list of good ideas. Your description of being hot, panicky, and sweating describes me perfectly when my thyroid comes "on-line" and I warm up. I'm not used to my thyroid feeling stimulated, with its interplay with the adrenals. Your mention of it being connected to vitamin C made me think about Dr. Abraham saying vitamin C helps improve the cellular transport of iodine. Made me wonder if the iodine is now getting into your body better. Also, vitamin C supports adrenal function, which might respond erratically at first to an increase in dose. Pick and choose if anything applies. Best wishes!
Abraham, G.E., Brownstein, D.,Evidence that the administration of Vitamin C improves a defective cellular transport mechanism for iodine: A case report. The Original Internist, 12(3):125-130, 2005
Lower blood sugar must have happened to me as well. I finally realized when I took 4 grams at supper I'd wake up in the middle of the night hungry. When I dropped it to 3 grams, no problem. Then I realized it was happening in the morning as well. I'm a little slow, but at least it's not making me hungry any more! :)