Hashimoto's disease
"I was on Levothyroxine for years (17). I have 7 thyroid nodules, and my physician is monitoring them closely. I begged my doctor to try Armour as I was so depressed, brain fog and felt the worst ever. I was put on 90 grains of Armour, within 6 months my tsh was .04. I was having tremors and racing heart. 
Apparently my body is extremely sensitive to Armour. I am now transitioning back to Synthroid/Levothyroxine and hopefully t3.
 Over the years your body changes (of course) - listen to your body. Everyone is different. Good luck"