I've been on thyroid medicine since I was 10, so about 12 years n...

I've been on thyroid medicine since I was 10, so about 12 years now. I started on Amour medicine and recently my doctor switched me to Levoxly which is the generic for Synthroid. And ever seen I started this medicine I was felt like crap. My hair is falling out uncontrollably, when I wash it, brush it, or just pull at it. My hands and feet fall asleep all the time. I'm still young and my body aches. I've experienced loss of libido and just in general I feel sick.