Re: Game broke, is repair trying to redownload everything?

@Winchestercester  Okay, here it is.  Cancel the repair, and restart your computer for good measure.  Without opening Origin, open Program Files (x86)\Origin Games, and move the Sims 4 folder to a different location on your hard drive.  Open that folder and move out all the pack folders directly inside it, as in, anything named EPxx, GPxx, or SPxx.  You don't need to mess with any other folders.

Open your Origin game library, and you should see the option to download Sims 4.  Click Download, uncheck all the packs on the list, so you're only downloading the base game.  Then pause the download, copy the Sims 4 folder you moved (still with no pack folders inside) to the Origin Games folder.  When you resume the download, Origin should verify the presence of the files and finish, rather than having to redownload everything.  It's still better to copy rather than move the Sims 4 folder though, because occasionally Origin will delete the files you moved and resume downloading from scratch.  You can then cancel the download and try again.

Once the base game is downloaded, you can repeat the process for your packs, starting and pausing the download and then copying the pack folder to the Sims 4 folder.  Stuff packs are so small they may not be worth the effort, but expansions are usually a couple GB.