That sounds like a good idea regarding the magnesium - perhaps you might take it internally too as a supplement such as magnesium citrate? Further to it being a companion nutrient to iodine, most of us lurking on these forums are usually in some stage of adrenal fatigue because of our health challenges, and magnesium then zinc are the first things to be depleted along with vitamin c from my reading..
The daily Iodine will really help you along with the companion nutrients C and Mag. The more I read, the sadder I am that half my thyroid was taken out - because I shrunk the remaining half significantly - and I'm now sure I could have shrunk the other half and elminated the pain in it too with Iodine :(. If your situation is anything like mine, you will have more health challenges without your thyroid than with it I suspect.
I would just send in an apology to the docs office so you don't get a cancellation fee... So glad you are keeping your organ and healing it!