Hey there!
I completely understand your anxiety about planes! I also have a very hard time flying, even though I've been on planes every since I was a little kid.
My most recent flight experience was so anxiety provoking that I threw up before take off.
I find that it really helps to take a huge bag of comfort items with you. Things that make you feel more comfortable and take your mind off the idea of being on a plane. I like to bring a bunch of books and stuffed animals. Also some pencils and pens for drawing. And music! I find that music is definitely calming and helps me forget that I am on a plane.

I also find that I'm more comfortable sitting in first class. I don't know if you want to do that or not, but that's just me. The seats are bigger and there's less people so it doesn't feel as crowded, plus you are the first person on the plane and the first to get off! I know it's a bit costly sometimes, but to me, it is definitely worth it.

I hope that you have fun on your trip!