The exact same thing was happening to me, but I didn't check or uncheck any boxes in System Preferences or edit the permissions... I was running Photos off of a 4 TB Western Digital HDD... which was slightly slow to begin with, since it was an HDD. After I updated to Catalina, the "Restoring: 0%" issue arose. I did a little research, and determined I should probably get an SDD to run Photos more smoothly overall, and having a drive that can read/write faster than my spinning drive was just generally good idea.
I got a SanDisk which was preconfigured and ready to read Mac's computer language. I plugged in both my WD drive and the new SanDisk drive at the same time, and dragged & dropped the Photos App from the WD drive to the SanDisk. It took about 14 hours to completely transfer everything (almost 1.5 TBs). I was worried that it might not work at first because for almost an hour and a half it said "preparing to transfer Photos" so I thought it would freeze or crash.
I let my computer take a break overnight, and the next morning, plugged in the SanDisk again, and tried to open Photos. It took about 8 - 10 mins for it to restore (it started with "Restoring: 0%" again...) but Photos is up and running again!
I'm not sure if what SenseOfLife suggested would have worked because I didn't find this until after the transfer was completed, but upgrading to a faster drive might help fix your problem too.