I've had panic attacks my entire life.Fortunately they're few and fair between these days and I can for the most part calm myself down when I feel one oncoming (they're almost always triggered by some event fortunately, very rarely just random ones).
I wouldn't wish them on anyone. That feeling of "I'm trapped, this is forever, I'm going to die, this is overwhelming, I need to escape" is genuinely the worst thing I've ever experienced. The brain misfiring the trigger that gets pulled when you're in a life or death situation is terrifying.
Fortunately recognizing that it's just a chemical response and I don't have an infinite supply of those chemicals and it will all be ok in a moment is one of the most calming thoughts and one that I always turn to when I'm panicking. Also remembering that I've felt amazing between panic attacks reminds me that soon I will feel that way again.
Just a few thoughts I turn to when I need to white knuckle that wave of panic that might be able to help someone else out.