Remember That Panic Will Pass
It's important to "recognize that panic will pass," says Dr. Wehrenberg. "A panic attack [usually] doesn't last for more than a few minutes. Then it wanes. So it's not going to last the whole trip. It will pass."
If you feel afraid of losing control and succumbing to fear during the flight, remind yourself that even a full-on panic attack is only a temporary affliction; you'll get through it.