Sims are disappearing after new game/trying to play with household

I haven't played the game since 5 months or so. I had two games. The second game totally disappeared and I can't seem to find the save file anymore. The first and original game I played is still in tact. However, when I make a new game and the first sim in the new game, they seem to disappear. I moved my sim into a household, but can't play because my sim in basically not there. I checked in manage household, but there is nothing to find there. I made a second sim, and the same thing happened again. I tried deleting the save file(s), but then my first (original game) gets removed as well. I tried turning off the mods, but it did not help either... Has anyone got any tips???