World Reset

Hi,

 

I was farming xp at my ender farm... using an ender chest a lot, i enchanted a lot of items etc... when i was done and i was going to go to my overworld... Note that my spawning point is not available to me occured and whole Overworld reseted, i had only items i lef Ender with and whole progers was lost... this was without any update of minecraft or windows 10 or whatefer... Can I Know how is this possible and is there any way to restore my progres cause i really want to play but this kind of makes me not want to if I have to start all over again and there is possibility of this happening again... Please tell me how to restore my progress