Armour's thyroid med is derived from pigs and actually has a really broad spectrum of action. Do you need meds adjusted? Synthroid just doesn't have the spectrum. Take some DHEA/Keto-7 form--doesn't form other hormones. Low doses are all that are needed and AS NEEDED! If you feel better in 20 minutes, you've self-diagnosed adrenal collapse. 5-10mg should do it. Or use the cheaper DHEA to see if that's what you need.
The thyroid under stress can overachieve and underachieve, yo-yo-ing through hypo-hyper-thyroid states. DHEA should help stabilize. Any chemical exposures? DHEA won't make you gain weight but should keep lean muscle mass up so no muscle wasting, see? Steady on!