I had an anxiety attack a few years ago. They're fuckin' scary. Anyways, I went to the hospital, had some tests run and everything was fine. Upon release they gave me something like 10 pills to take if I ever felt myself in the same situation. Maybe once I was close, but I refused to take one of the pills. I've just learned to calm myself down...not that it happens regularly.
I'd suggest the obvious and talk to your doctor about the potential hazards. Perhaps there's a weaker drug they can put you on to help ween you off.
