Almost my whole Pizzeria, we created after 3 hours of work, just disappeared

So, on June 26th me and my friend were playing Minecraft and we decided to make a Five Nights Freddy pizzeria and it was really big and it took us 3 hours to build it. But then my screen went off and I went back in and it was gone and the only part that was
there was half of the floor and me and her spent so much time and effort on it and the thing is that I deleted the world cause it was no use.

Gamer Tags: Katekitten23 and ThugShelby
Name of World: five nights at freddys