There are ways to manage your fear...

Have with you some sort of object that is comforting.

Take some benedryl or gravol prior to the flight.

Just don't line up. The plane isn't going to leave without you. Wait until the line dwindles to the end before you approach the boarding gate.

Reserve an aisle seat preferably at the forward end of the cabin. Not seeing a sea of heads helps to ease the claustrophobia as does not being hemmed in by other passengers if you are sitting at a window.

Let the attendant crew know you are nervous. They can help you cope.

Chat up the person sitting beside you if you can.

Bring/purchase earphones and take advantage of the in-flight programming.

Think of what you will be doing after arrival.

While these things won't erase your worries they likely will help you cope. Good luck and bon voyage.