My 10 year old survival world has now had 3 glitches over the last few months mainly due to random chunks over riding custom villages and my landscaped gardens around my base. Each time I have just “got on with it” and fixed sometimes improved the overriding infestation.

last night after logging off my main world after about 100 hours of fixing the latest attack I opened an old copy world (3 months old) I have never used coordinates and wanted to see if I could map the area to find a “chunk” to build a farm on. No cheats no anything just coordinates. 
I open up my main world today …different Xbox name and my world that has been rolled back again to sometime before BUT the shulker  box I was using last night is still sitting there!  All the candles, dungeons, pathways, custom trees, mob spawner redesigns are gone!  Hours upon hours of work ALL GONE! 
WHY?
My will to play is just ….