Sorry that this happened to you. Yet Ill put my input in it.

This happened to me alot the past year, and then i was put on zoloft to calm myself down. I was having panic attacks, because of my side affects on a medicine, and then it would scare me into a panic attack where i couldnt breathe, got very weak and hurt in various places.

Though most crisis's come on semi slowely, it also could be that. Yet the fact that you got better quickly is a good sign.

Hope you feel better!