Re: Could I be Hyperthyroid? Confusing labs.
I don't know a whole lot about hyperthyroidism, and your case doesn't seem simple. I did some digging around at reputable medical sites to see what I could find out for you.
There's a condition called "subclinical hyperthyroidism" that seems to fit. (Wouldn't call yours a "classic" case, but it's close.) This presents with low TSH and "normal" FT4/3. There wouldn't be "overt" hyperthyroid symptoms, although "nonspecific" signs or symptoms such as malaise, tachycardia, nervousness, and anxiety may be present.
Your MD is mistaken to use the total T4 test to try and diagnose this. Total T4 can appear low, but when the more accurate free T4 test is used, it can be markedly higher - even excessively high. The free T3 test must also be run.
I can't explain your increased symptoms following the FNA. I'm only guessing here - really guessing - but perhaps the intrusion of the needle into what might be a mildly "hot" nodule caused a surge of T4 to enter your bloodstream... ??? Don't take that as being in any way scientific... LOL
So... Get the right bloodtests, both free T4 and free T3, and go from there. Hope that helped, at least a bit.