I agree with grizz, I didn't have nodules thank God because I didn't do my homework before using Iodine like I should have. I was really Iodine deficient and had similar symptoms as you, but didn't take enough selenium before starting Iodine and its really bad. Will be much worse for you since you have nodules.
Your symptoms are obviously thyroid problems related to iodine deficiency, so you would need selenium for a long time before slowly starting on a really low dose of Iodine.
I would suggest mcg then graduate up to mg doses with Iodoral/lugols, or SSKI sold here by trapper.