I am also dealing with anxiety right now. I can be fine for months, and then have crippling, constant anxiety for over a week before it finally subsides. I think the trigger for me might be lack of sleep and stress.
I keep asking myself "what is going on in my head? what is wrong with me?" At times I think it feels so awful, it has to be more than just a panic attack, but the pounding in my chest, the shortness of breath, the numb arms, the sweat around my neck reminds me that it's just the same ol' anxiety that eats away at me again.
I know it is not for everybody, but reading the bible, and the "read for inspiration" thread on here has become my "safe place." It is where I go to when I am suffering anxiety. It offers a bit of hope that there is more to this world than what we can see and touch, something that transcends the scary thoughts my mind is pulling out of nowhere. Nothing can take away the horrible bewildered feeling of impending doom, but I keep reading until I can catch my breath.