Entire game progress has disappeared

I play Sims 4 via Steam. Since the new update, my entire game progress has disappeared. My mods are disabled, and script mods were already disabled before the update and were therefore not in use. 
When I started the game for the first time after the update, all my DLCs were displayed as if I were playing them for the first time. Unfortunately, I now only have the option to start a new game.
However, my library with the houses I have built is still up to date.

Does anyone else have the same problem and was able to fix it?

EA Support was unable or unwilling to help me with this issue.