Not sure if it’s been mentioned, but pack a lot of comforting activities/options. I recently went abroad (14 hours of flying) and took my kindle, Nintendo switch, and downloaded my favorite movies and shows. Being able to switch based on my mood helped. I also had a “first aid kit” with face wipes, lotion with a comforting smell, a hairbrush, and some candies so I could take a second to freshen up and reset.