There is no relation between adrenal gland exhaustion and thyroid. When adrenal is exhausted, thyroid deficiency if present along with, is not replaced till adrenal deficiency is corrected. You have heard wrong information from general public, giving thyroxine does not make thyroid dead. Your advisers are ill-informed. There is no relation of stress and thyroid. Use iodised salt, nothing else is required, nor can be done. Believe scientific information and not hearsay.