My panic attacks are usually more emotion than thought. Usually, any thoughts about what I'm panicking about are brought up as a result of me feeling anxious about nothing in particular. I just obsessively remind myself that I'm having an attack and to breathe. It goes a bit like this:
Body: EMERGENCY!!!
Me: Oh crap! OH CRAP!
Me but smarter: EMERGENCY! We're freaking out for no reason! Remember to breathe. We're panicking. Don't worry. Breathe. Breathe.
Me: *breathes* this is still bad. Something is awfully wrong.
Me but smarter: nothing's wrong. You're just having a panic attack. It'll be over soon, just breathe.

Then I sit through the rest of the panic attack, but now with the knowledge that it'll end. It still takes a while, but for me, knowing what's happening, and acknowledging that that state of being is temporary really helps me. I don't know if this'll help. This is just how I manage.