Old Game replaced with new game on load game option

Ok, so I don't know if I am just a noob, but recently I made a new world on the sims 4. After playing a little bit, I left and the next day got back on to play my old game. But when i tried to load my old game, it said i was loading my new game and I have no idea what to do😕mileysad:! For example: New game is called Russell, old game is called Smith, when I try to load Smith after playing Russell, the game thinks I am trying to load Russell, not Smith. Does that make sense? Please help, I worked really hard on my family! ☹️