I've only had one really insane experience like this, but I've had hundreds of minor panic attacks. The key for me was learning to control it before it spirals out of control. The problem with panic attacks is that they're recursive and only stop when your stack overflows :-)

I've trained myself to exit() the second I notice my mind going down that path. I tell myself "DONT FUCKING WORRY. YOU'RE FINE. THE ODDS THAT YOU'RE DYING VS HAVING A PANICK ATTACK ARE REALLY LOW! NOW SNAP OUT OF IT!". One thing that helps me a ton is to reach for my phone and start reading Reddit or Hacker News or something familiar to engage my mind in something until it calms its stupid ass down. Sitting down helps too, just to relax myself.

The other thing that I found is that being tired is the biggest factor in my ability to control my mind. Being well rested is essentially a cure for me.