Game crashes when I try to open my world

I’m locked out of my world. I’ve been playing in this super flat world for a few months now on single player. I wasn’t doing anything mote worthy when I quit and save. I made a back up of the world and went into a creative world. When I tried to go back to my main super flat world the game crashed. I restarted it and again. Restarted it again and tried the back up world. It crashed the game as well. One thing that may have caused it was that the last time I saved the switch was on airplane mode. I don’t think that would matter but thought I’d mention it. I’m really devastated, today is my birthday and it sucks that I’m locked out of my world. I hope someone can help me get it back.