Well good luck with trying to do it yourself. As for normal range, lots of people suffering from the condition will argue that what is normal for one, isn't normal for another, it varies according to each person and I just wish doctors would acknowledge it. Have you had blood test for serum ferritin, that may help advise too but then again docs are reluctant to do this, thyroid patients often have to fight for help because of the range for the tests as explained above. Hope you manage to get sorted, look up avoiding certain foods they say for thyroid patients, it might help you never know.