My Minecraft Worlds won't show up

I went on a trip a few days ago and when I came back my some of my worlds were not there. Some of them might have been deleted or corrupted but I think that they should fix this issue because I spent so much time on the world I lost and I had even built skyscrapers that took months and now I can't get it back. I really need Minecraft to fix this issue because it is really sad that I don't have my world anymore and I think I might just quit because of this. I also think we should get a way we can recover our deleted worlds because sometimes we accidentally delete our worlds and I feel like there just should not be a delete world option because you never know how much you would want them back. So in summary there should be a way you can get your worlds back after deleting them and they should stop our worlds from getting corrupted or the worlds getting deleted on accident or because of a glitch.