Lots Disappearing

Hi there, I have run into an issue where when I build on one lot, when I load back to the world everything else that i've built either completely disappears or reverts back to the base game build.

I spent over 4 hours building on a lot in Raven wood. (mind you, the save I was in I had spent all day clearing all the lots to be empty) When I left the lot I was building on all of the base builds had spawned back and overwrote all my other builds. My households were still on the lot but all of the work had been lost on a save i've had for 3 years... 

Is this just happening to me and my game?