I have been on anti-depressants/anti-anxiety (Welbutrin, Celexa, Lexapro and most recently Cymbalta) for several years now with great results. Within the past 2 months, I started having what felt like panic attacks which included difficulty breathing, heart palpitations, tightening of the throat and hot flashes. My doctor decided to give me Ativan to curb the anxiety. Mind you, my attacks were not 15-30 minutes, they lasted from morning til night. After several weeks of no relief, he switched me to Klonopin and changed my daily meds to Cymbalta. My depression is fine at this point but the anxiety medicine has no affect on me. I can't breath normally from the time I wake up until the time I go to sleep. I have cut out all caffeine and have been excercising and eating right for several years. I am wondering if this is actually a problem with my thyroid. I am in transition between doctors and just wanted some advice. Any thoughts?