If im reading this right, your feeling this bad came about very recently, right? We all have that now and then. Its always really bad right after you've had a stretch without attacks, because as i'm sure you know, it's hard to even remember what one from an hour ago felt like. You just have to keep reminding yourself that its just panic, that you've felt this way before and every time, you came out perfectly fine.
Really, that you're having those same symptoms and they never hurt you before suggests that having them again means nothing's wrong at all, just like every other time.
If you want something to help immediately though, you just need to find something to do with all that adrenaline. I read and listen to scary stories. I know that sounds silly, but it lets me have a real, scary thing infront of me to focus on, with full knowledge that i can end it at any time. Its an outlet, so I can stop looking for threats. And its astonishingly successful in doing so.
Your mileage may vary. But it sounds like you are already terrified, so there's no way it could make you feel worse. May as well try, yeah? Here's a fun one: http://youtu.be/-gXtjUTWFPc
Just...try not to look at the picture too long, yeah?