Something I read once when I was mentally preparing for flying..go through each step of the flight..leaving home-> checking in at the airport -> boarding -> flight -> arrival.. going through these steps might help you feel more prepared. I hope it helps
I would also take lots of vitamins, fish oil etc etc to keep your body fit.
Music, books, pencil and paper, games, movies etc are also good ways to distract yourself. With me it's not working because once I'm in panic mode it doesn't go away until I can retreat somewhere quiet I hope there is something that helps you get through the flight.