Re: saved sims to my library, quit, and now they're gone!

@PicklePizza6  So if you bring up your in-game library, the sims aren't present?  Did you happen to save the household to the Gallery as well?  In either case, you may need to check the box to show custom content in order to see the household.

If that doesn't help, check Documents\Electronic Arts\The Sims 3\Tray for any files with the same timestamp as when you saved the household.