If one world is consistently crashing on you and won't load, and if you can go into other new or existing worlds just fine, I'm sorry to say that the crashing world is very likely a corrupted game file now and cannot be recovered. When going in and out repeatedly of a world, make sure it has enough time to save the game, going too fast can interrupt the save process and corrupt the file.
Hopefully, you've taken advantage of the extra save slots and manually made backups of the world before it was corrupted, explained here:
Mobile Backup Instructions
Sorry I don't have better news. If you'd like to talk with 505 Games directly and see if they have any better news about your issue, you can open a Support Ticket with them here (you'll need to make an account to open a ticket):
https://support.505games.com/en/support/home