World got Reset

I went to play minecraft, and i was suffocationg in a wall. I dig out and I find that while I still have my stuff, and my animals are alive, everything I built is gone, and I have new 1.18 generation. I had just played using the snapshot, then decided I wanted to use 1.17 so I switched to that.

EDIT: I had a backup of the world from before it got reset so that one works, just can't load 1.17 and have to use the snapshot