If my Hashimotos is under control what can cause the pain and fatigue?

I have Hashimotos, I had half of my thyroid out Feb 7, 2007. I have been getting my TSH checked and my thyroid seems to be under control. I have pain in my abdomen, my legs, my knees feel arthtritic, and my back hurts. I am also fatigued and want to sleep all the time. Im starting to get depressed, my husband dont know what to do to help me anymore. Ive been to the ER and they dont know what it is. I was on a waterpill that depleted my potium, but it is back in to normal range. They suggested a rheumatologist, but I cant get in till July 23. My neurologist is wanting to switch me from synthroid to something else. What else is there? I didnt know anything else existed. Are they better and do you think those will solve my problems? Im just getting tired of feeling this way, I havent felt the same since the surgery. Thanks