Mac Mini Won't Boot

My Mac Mini is set up to have an admin account on the main internal drive and a user account on an external drive which is the account I use 99% of the time. I accidentally disconnected the external drive and I am now unable to boot to that account. I get an error that the keychain can't be found with the option to cancel or revert the keychain to defaults. Either option results in a stuck loading screen with not progress.

The admin account boots fine, and I have restored the external drive to the previous day using Time Machine but there is no improvement. What should I do to get the user account back to normal?