Corrupted World

I was updated to 20w07a, acquired some of the new items that were released, such as Ancient Debris, but I go on Minecraft today and I was no longer on 20w07a. I was not asked to backup anything before going onto my world, so upon logging in I realized all of the new items were no longer in my inventory. I spent a lot of time acquiring them so it is frustrating that I no longer have them.