@TahliaSalan Repairing a pack in macOS is a bit more complicated: you'll need to delete the pack and redownload it. Here's a visual, in case it helps:
https://bluebellflora.com/2020/06/17/repairing-sims-4-packs-in-origin/
You can definitely save your progress in the new save and go back to it later. Worst case, you'll need to replace some items after the pack content is back.
@TahliaSalan Sorry for the late reply. You should only need to delete and redownload the folder for the affected pack(s), so start with City Living, which is EP03. Run the Origin reset tool for macOS and restart your computer before redownloading it.
https://help.ea.com/en-us/help/origin/origin/how-to-reset-origin-on-mac/
@TahliaSalan The llamas in the worlds are usually caused by another missing file in the corresponding pack folder, as described in Bluebellflora's article I linked earlier. Did you specifically delete the EP03 folder inside "The Sims 4 Packs"? There are other folders also named for the packs, but they don't contain the files responsible for loading this data.
If you're having trouble with a number of packs though, you may need to uninstall and reinstall the entire game. The most reliable method would be to uninstall, run the Origin reset tool, restart your computer, and download only the base game. Then load the game, have a look around, and if everything is fine, download just one pack and check it out too.
Origin will try to redownload all your content at once unless you stop it. In Origin, before you've reinstalled the base game, disable auto game updates. Hover over your username, select Application Settings, and under "Application" (the first header), scroll down to Client update and disable automatic game updates. When you first launch the base game again, Origin will still try to download the packs, but you can manually cancel all the downloads. (The download manager can be expanded by hover over it, in the lower left corner.) Once you launch the game, use cmd-tab to switch back to Origin to stop the downloads.
If you want to preserve your saves and other content, please move the entire Sims 4 folder out of Documents\Electronic Arts and onto your desktop before unintalling the game. This folder is supposed to remain intact even through an uninstall, but sometimes that doesn't happen. However, if you move it or save a backup copy somewhere else, you can put it back later with no harm done.
