Extreme world corruption

I was building in my long term survival, a completed world that I've dabbled in since a while before the ocean update and the village and pillage update. I had a giant base. A huge farm with automatic sugarcane and various other automated farms that all shuffled into an automatic sorting system. I spent tons of time building in this world. Then, I opened it again. And excited my house to see what looked like an unrendered chunk. I walked up to it as if it weren't there, expecting it just to be slow rendering, then I fell in. I died. It wasn't until I responded until I noticed that nearly all of my work. My countless hours of time building in this 193Mb world, had all been corrupted. Random chunks of terrains that were not originally here had replaced large sections of my world. Huge pieces of the landscape had been completely deleted leaving holes to the void up to 5 chunks wide. My 120 block tall house had been reduced to a 10 block tall house, with the topmost section completely vanished from existence. My 193Mb world is now reduced to a 111.3Mb. (This world was large because I started it on Minecraft Xbox One Edition before bedrock edition was on the Xbox). The title of the world, once labeled "Hard Survival" as it's on hard mode, now is just a blank section.