My spousal unit feels much as you do. He was never the world's greatest flyer, but then about five years ago we had an emergency landing (that turned out to be nothing), and ever since then, he really does not like to fly. Me, OTOH, I really enjoy flying.

Here's what I have noticed helps him:

Window seat. Looking out the window seems to soothe him like nothing else does. He takes pictures of the view, and that keeps him entertained.

Good IFE. Most airlines today have a decent to good selection of television shows and movies. That can keep your mind off your troubles for a lot of hours. If your airline is deficient here, load your iPad (or equivalent) with movies, television shows, music, books, and magazines. In fact, just load up on this stuff to your liking and you will have a much more enjoyable flight and trip. There's nothing worse than being abroad and finding yourself alone in a hotel late at night, with nothing to read and nothing on television but late-night shows with which you have no familiarity. I like taking books that have something to do with my trip (The Blindness of the Heart for Berlin, Borges's short story collections for Buenos Aires, and so on). That way, if I am reading on the plane, or during the trip, I can sort of imagine the place I am visiting in someone else's mind.

Get a look at the seat map and figure out where you will be sitting, what the configuration is, where lavs are, etc. Knowing this information in advance can make you feel a little more in control of your environment.

Take any small food item that makes you feel comfortable with you: a candy bar, a particular type of tea or herbal infusion, a small box of chocolates. Just remember, keep it small, and no liquids until after security.

Turbulence is normal in flight (just like hitting the occasional pothole while driving is normal). You'll be fine!