Sims 4 Deleted Saved Game

I have a similar issue! I've played the Sims 4 a whopping 100+ hours with no problems. When I initially started playing the game I accidentally had on the option that non-playable Sims also age, which resulted in a whole lot of old people in my neighbourhood (as in in-game families like the Goths etc). After making and playing with a bunch of families I grew tired of the old people and decided to edit the existing families, add some kids and teens and adults in the mix. This worked just fine as well. However, this morning when I started my game I realised all the families I had made from scratch and played with had disappeared. All houses I have built are still there, but they're vacant, and the families that used to live there have disappeared. What happened and how can this be fixed?! It's not the end of the world because I had pretty much played myself bored of the families already, luckily the houses are still there! But I still want to avoid this happening in the future...