"I started an elemental diet 1.5 weeks ago (basically amino acid powders and no real food"
concentrated amino acid powders could cause problems; they frequently contain nasties like Aspartame etc. I would check the ingredients list carefully.
Side effects of amino acids depends on which amino acid is being used. Some are practically harmless, whereas others, such as tyrosine, can cause anxiety, restlessness, rapid heart beat, and even heart palpitations on high doses.
A steep drop in Iodine is no problem, other than after a while the symptoms for why you took Iodine in the first place, may come back.