At the risk of sounding like Trapper, maybe you should have painted more not less?
Or actually, just carried on painting (or painting on your heel, like you suggested).
If your thyroid was as deficient as you said, then it seems likely to me that the rest of your body would also be deficient, as I understood that the thyroid had "first pick" of any Iodine going.
I'm open to correction of course.
Thanks for your posting anyway, which is instructive.