Yep, air hunger is my biggest sensation these days. That's a much better way to describe it than "shortness of breath." Because for me, I can tell that I am breathing, even my little med devices (pulse oximeter and peak flow meter) register fine, but I feel like it's not doing any good. And, yes, for me too, once that kicks in, it's hard to stop the anxiety avalanche, because I become convinced that I'll pass out or suffocate.
I also get a sort of chilly feeling in my chest and (very, very rarely) a sense of disconnect.
I was diagnosed and am now being treated for acid reflux, which caused an awful lot of my breathing symptoms. So now that I know they are the result of either reflux or anxiety, neither of which can hurt me, I consciously chant that to myself until I can get a grip again. It's not easy, but it's been working lately.
Good luck and keep posting! We're glad to have you here!