I would think about the types of situations that trigger the anxiety attack and what works without drugs to deal with the situation. With my wife the first day of a trip she would experience similar problems but was OK after that for the duration of the trip.
The anxiety can be physically driven or mental (brain chemistry, etc.) and with the mental aspect it is helpful to know that you are having an attack and that the anxiety is not "real". I have taken meds that have this as a side effect and stepping outside the moment and realizing that this was happening helped a great deal. I would then take a walk until the effect was over. Others may find meditation more helpful in such a situation.
There are meds you can take but these all have side effects unlike meditation and are a more mechanical solution of the type favored by western medical practitioners.
Worth taking the time to find sources for information on dealing with anxiety attacks and how others have managed to deal with the problem as there are going to be differences between individuals.
With regard to camping suggest taking short 2-3 day trips initially and then progressing to taking longer trips.
Above all else do not take any firearms on your trips which would only compound the problem for you and for others.