CAS deleting my Sims

Hey, I just created this account to voice my concern and very big issue. 

So I was currently indulging in the Not So Berry challenge, as one does. I’ve been working hard, I was even on the 6th going on the 7th generation on the challenge. I’ve been playing like normal, but the only difference this time was that I had just gotten the High School Years ExPack. As I was playing, I thought it was appropriate time to change the appearance of the parents. Usually I go through the mirror to then go to CAS. When the loading finished I saw a Sim that was newly generated. At first I thought it was odd, and just clicked out of CAS, just because it was a “glitch.” A meaningless glitch, one would assume. I went to save in case anything got worse, so I wouldn’t lose any of my progress. Then when I went to see where my household was living, none of them showed except for a glitched loading symbol. Yet the apartment showed they were still there. So in wishful thinking, I exited and went back to the previous save, just to find no Sim to be in the house. No trace of that household. Progress lost. 

I’m not sure what do about it. Or even if I’m able to do SOMETHING about it. But hopefully this is a cautionary tale to those who encounter a similar glitch.