I also get nervous about flying, and 9 hours does seem like a long time.
My advice would be to break it down into chunks, and plan/visualise what you are going to do for the 9 hours.
0-1 Hours - Settle in, and listen to some relaxing music, or a favourite album. Eat some sweets.
1-3 Hours - Watch a film.
3-5 Play a game on your phone.
5-6 Rest/Sleep
6-8 Watch another film, or me on YouTube.
8-9 More relaxing music and sweets.
Have you got someone who you can message/text on the flight there? I find having someone to talk to, or just get some positive vibes from is amazing help. You don't feel so alone or isolated.
Another piece of advice when I am struggling with anxiety... act like someone who does it all the time, and doesn't have anxiety. Sounds stupid but it works.
Last thing I would suggest is getting diazepam from your GP to take before. It will take the edge off, and will give you a relaxed feeling without the need for booze. They don't really cause drowsiness either.
Good luck Carrie!!
p.s logged in out of curiosity, and had to respond!