@ayyamandaa Your Sims 4 user data—your saves, saved builds and housholds, downloaded mods and custom content—is stored in the Sims 4 folder in Documents\Electronic Arts. You can back up this folder in its entirety, either to an external device or to somewhere else on your computer. So no matter what happens to your current copy of that folder, you'll have a spare copy to restore if necessary.
Please clear Origin's cache (Windows) or run the Origin reset tool (macOS):
https://help.ea.com/en-us/help/faq/clear-cache-to-fix-problems-with-your-games/
https://help.ea.com/en-us/help/origin/origin/how-to-reset-origin-on-mac/
Restart your computer, and try to repair again. If this doesn't work, please let me know whether your computer runs Windows or macOS, whether Origin shows as online or offline, and whether you get an error when you try to repair. If you do see an error, please post a screenshot.