This probably won’t be a popular take, but get a Rx for Ambien. After years of suffering from jet lag on international travel, I finally started using it about 10 years ago.
I usually only take 1/2 a pill and only if I wake up after going to sleep.
Makes a huge difference. Allows me to get more sleep at night and I still wake up fresh, not groggy.
For your trip, I’d consider taking a 1/2 pill once the plane takes off…it will let you get to sleep at a time you aren’t used to and then arrive better prepared to take on the day once you land.
Some people have weird reactions to Ambien, so definitely try it at home first and only 1/2 a pill.
I call it my Vitamin A regimen. 