You know, I have Hashimoto's too, and I find that levothyroxine just does not work. Try getting your doctor to switch to the namebrand stuff...Synthroid. It makes a big difference!!
Also, It takes a while for your dosage to become correct as they have to keep testing and leveling it out and so forth, so just give it time, trust me, once you're on the right dose, you'll see a difference.