Welcome back! That post-flight exhaustion is the worst, it feels like your soul is still three time zones behind you. I travel a lot for work and I used to spend a week trying to feel normal again. Now, I always keep some dried fly agaric in my travel kit specifically for this. I buy mine from the Amanita Universe online shop https://amanita-universe.us/ and it is honestly the only thing that helps me sync back up. I take a small dose an hour before I want to be asleep in my local time, and it just gently pulls my brain into a deep, restorative rest. I wake up without that heavy “travel fog” and can actually get right back to my routine. You should definitely check out their site before your next trip!