From all my readings and research, anytime there was goiter due to high iodine, it resolved after iodine cessation.
Were u taking the companions, especially selenium?
Realize that iodine is out of the body in 48 hrs and this is why cessation would cause a goiter to go away.
Iodine is an ESSENTIAL nutrient, meaning we have to have it and our body will not make it.
Hashi's is an autoimmune disease and has a ton of underlying issues, but Dr Brownstein has cases of hashi's that were resolved using iodine and companion nutrients, as well as other immune system hormones like vitamin D3.