my game deleted itself

So my game deleted itself. I was playing i went to go get dinner. I left my xbox on and its really old so it overheated when i got back. I was in my game in the process of making a farm of zombies and then it overheated. I thought nothing of it but when my xbox came to its senses and was fine I couldn't find my game. It was no where. Only copies existed and those I was checking something like the nearest village in creative so I cant get any achievements from them which is very frustrating. That is all

 

 

 

(slendertummies was the original name before i changed it to "idk")

 

also idk if this is minecraft's fault or my xbox but i am very frustrated since i had over a stack of diamonds and other things of value like my named fish llama and gerald i miss them