if you dont want cancer, take selenium. if you dont want hashis, take iodine.
pulse and work up to 50-100mg. you have to get over the hump. fortunately, youre in control. people dont believe it till they do it but getting up to 100mg usually does the trick. amazing but true. after that you can take just about any amount you want, within reason of course.
look over the companion supplements and salt loading for further help.