iodine is out the body in 24 hours. if problems get worse after stopping then its because the Iodine is gone. it takes time for the thyroid to adjust. your worry will provide you with a self fulfilling prophecy.
100mg minimum. you can take more than that and see if that helps.
my guess is that you are hydrated. push the salt and water, too. you have drought in your thyroid. anything else you can do to increase circulation like rebounding and sweating.
iodine does not damage the thyroid. the stuff thats coming out of your thyroid, well thats a different story. keep it moving with Iodine and down and out with good bowel and bladder eliminations.