Good advice PanicCured... I think what you say about the nervous system being on high alert makes sense from a practical stand-point (especially when I consider that it feels like my anxiety and associated symptoms come and go in cycles of some kind.. that it feels to me like it builds up).

The part I wondered about -- I actually have anxiety surges / attacks caused by my breathing. What I mean is that I start "noticing" my breathing when in an anxiety state, and it typically causes more anxiety. By notice I mean I pay attention to it, scrutinize it even, which inevitably causes me to mildly hyperventilate (as you said, never feels like I'm getting enough air) making some symptoms worse. This is one of the reasons I've avoided deep breathing techniques... personal experience has taught me that not thinking about how I breath is better for my personal anxiety state in general. Can you relate to any of what I'm saying, and do you have any suggestions?