I used to be really afraid of flying. Days before a trip I would get so stressed i would be sick, and i would stay sick.
I had to get meds from my doctor just so i could calm down some.

Over time i did get over my phobia. Now i can fall asleep during takeoff. Heres my strategy:

Try to sit in view of the attendants. This is routine for them, and they done it a million times, its just another day to them, and perhaps you will find that comforting.

If you cant feel the vibrations of the aircraft, it makes the flight seem a bit less real, and you can imagine you are simply in a a movie theatre. Try putting your feet on your luggage, or use the bar from chair in front of you.

Its a blessing when the pilots announce prior to trubalence that the chance is likely that the plane will see some. Its nice to be prepared, and its nice ot know that the pilots are prepared as well.

Bring a book, or a crossward  puzzle.  Anything that can hold your attention and  shift your focus. A good magazine is excellent.
In  the end, after you do this enough, it will become a second nature to you, and you will find yourself increasingly more comfortable with air travel.