I accidentally deleted my game a few days ago. But, I discovered that all the old auto saves were backed up automatically to icloud (thank you apple!). All I had to do was move the most recent one into the saves.
I'm sorry that happened. I have lost games in the past and it really sucks. Nothing quite like losing hours and hours worth of progress. I used to back up Sims 2&3 on a thumb drive, if you don't have icloud, I'd recommend doing that from now on since it seems to give you a hard time.