Sera-
I read in "Treating & Beating Fibromyalgia & CFS" by Dr. Rodger Murphree that GABA (Gamma-aminobutyric acid) is something that helps with anxiety and panic attacks. I have not tried it, but 500mg-1000mg 2-3 times (or as needed) per day on an empty stomach seems to be the recommended amount.
Hope that this helps and you will feel better soon!
Cyndi