Lost my world

Game keeps crashing when I’m loading into one of my worlds. The others work fine but this one has problems. Before I had this problem, I was able to load into the world but there were a bunch of rand blocks and paintings on the ground and my game was really laggy. I couldn’t go through nether portals or open my inventory sometimes and the world wouldn’t load in. I also couldn’t leave and save cause it would load for hours. After the world started to get better it crashed and I haven’t been able to load in since.

*the world has been deleted and I can’t get it back. I didn’t delete it.