Steve, if your blood was in the normal range before RAI, you must have been on some kind of anti-thyroid medication. Perhaps it has dropped back in the normal ranges now from the RAI, which is good. That doesn’t mean you feel good! Being hyperthyroid has strong effects on all the body tissues, and it takes many months to get over that for some people. You might start going hypo pretty soon, and that can be very difficult (I have just been going through that)! It may be a very long time before you feel “normal” again, so hang in there!
Did you ask your doctor any of these questions? He is the only one who can know what’s really going on with you, and why. I am seeing my endo later today, and am writing down my questions so I don’t forget to ask them (thanks Bruce)!