HELP - gone on sims and no families/anything

@Clearist  Do you use OneDrive?  (If you're not sure, please check—it sometimes enables itself after a Windows update.)  If so, your files may have been uploaded to cloud storage and removed from your hard drive.  Please check OneDrive's Documents directory for any Sims 4-related content.

If you don't find anything there or OneDrive isn't active, you can search your hard drive(s) for your saves.  Open a File Explorer window, click This PC in the left panel, then enter Slot_ in the search bar in the upper right corner.  This should turn up any save files on your computer.  If you find them, highlight one and click "Open file location"; you'll land in the folder where your saves are.  You can move them back to Documents\Electronic Arts\The Sims 4\saves, and the game should read them again.  This also goes for any Tray files you see in the same location.