MacOS Contacts are blank (but still in iCloud)?

So I had 150gb of System Data, followed a tutorial on deleting tons of old stuff and did so. All is good except now my Contacts are empty (which effects Messages, Find My, etc). Everything is still there in iCloud on my iPhone and iPad. How can I force Contacts to update? I've tried turning it off and on in iCloud > Save to iCloud. Please help?