I can relate to this.
I didnt use to sleep on planes too but when I started taking flight over Pacific (LA to Pakistan) with 14 hours non-stop over Pacific ocean, I changed my habit.
I used to make myself dead tired a day before the journey and normally did not use to sleep a night before. That helped me take 6-8 hours non-stop sleep on the plane. with a note to Air hostesses to not wake me up for any meal…
made my life so easy!