Does anyone have difficulty breathing? I can't seem to do anything at all without getting really out of breath. Dr. seems to think it's anxiety, but I don't FEEL anxious, just totally exhausted. It's like I'm so tired I can't breathe. He doesn't seem to think it's a heart problem, has looked at pulmonary function tests (they're ok). Put me on Lexapro (3 weeks now) and I can't see much difference yet. Could it be asthma? Help.