Synthroid and bummer

Where to start!! I was also put on Synthroid and have been on it now for 6 months, before that I could hardly get around and thought I was lazy. It has been changed 4 times and now I am on 88. My legs ache all the time, cant sit for long periods of time, they drive me nuts. I take Xanax at night so I can sleep but I wake up 3-4 times a night and cannot hardly walk they are so stiff. Does anyone know what the heck is wrong? I am on 12 different meds for COPD and an aspirin every day from a Heart Attack and Bypass, truly a bummer. I was so active before all this and could think on my feet, now I am just completely forgetting everything.