Yours is a unique question here, since we deal with Graves’ Disease, and it appears that was never your issue. Your uptake test may shed some light on what’s going on. If you don’t need Synthroid, you shouldn’t be taking it (it would make you hyperthyroid), but if blood tests didn’t reflect a hyperthyroid state, that’s extremely odd, and something we could not speak to.
The one thing that MAY be of help is that we know the range of normal thyroid hormone levels is enormous, and what that means is different people feel normal at many different points along that range. If YOUR normal is "low" on the scale, then having your levels in the upper part of the scale would lead to YOU become hyperthyroid.
I am certain that you need to be a team member in this process, so make sure you learn all you can about what’s been going on, and what the doctors are proposing in terms of tests and treatments. No one cares about you as much as you do, I guarantee it. No one is going to put as much time into figuring it out as you will.
Unfortunately, I don’t think we can provide much guidance for you. We do wish you luck!
