Over 100 hours of building lost.

I've had a bug with the game opening for a few weeks< but once I fixed it, I logged in to find literally 100+ hours of building and playing GONE. Its reset to Dec 30th. I have no idea what to do, but I'm about to breakdown over this. Building and goofing off in this game is my way of letting off steam and relaxing. I know it sounds dramatic, but I'm so stressed out, and I'm at a loss. I'm going to play on a different save so I don't have to think about it right now. I tried recovering, but the only options are two different times on the 30th.