I really don't know a lot about over-active or under-active thyroid conditions, at least as far as home remedies. Maybe a visitor to my website would have some suggestions.
As far as it being connected to Restless Leg Syndrome that could be something to wonder about. I know even the medical profession don't know much about what causes RLS or what to do about it. I did write a page about RLS and a strange remedy I found out about. If you're interested in reading about it just go to the button on the left that reads "Home Remedies" and scroll down until you find the link about Restless Leg Syndrome.