Hello Ali

I had to fly from Michigan to Japan, before I new I had RSD, my Mom was with me,

But I had my Dr write me a note that I needed to board 1st and not wait in the long lines, and the use of a W/C they will take you right thought everything
at least here they did for me and in Japan,they took me right though everything it was so much easier , also they took all bags and my mom did not have to do anything they did it all, so that can help your mum also
also you can ask for a seat on the plain that gives you more room if you need to lay back more, there should have handicap seating on the plain,
call a head, and when you get to the air port, let them know and if you have a note from your Dr make sure you give it to them, and someone should take you right thought everything,
my flight was about 24 Hrs also, and it was not easy, on me, but if I did not have that note from my Dr, it would of been a lot worse,
I hope you have a great time there, and enjoy your trip,
so ask your Dr soon and if there are more needs you need to fly, then make sure you get your Dr to ask for everything you need, ok

take care
and have some fun there!
Peace

PS take your own pillows and a blanket if you need it, the ones on the plain are not soft and the pillows are to small,, or big enough,,