Figured it out! I noticed that some pages had an ID of 0, and checking the database I saw that auto_increment had been turned off. I turned it back on (through phpmyadmin), renamed the 0 to an available number, and it’s working again.
To disable the plugin, just go into the /wp-content/plugins/ folder and rename the folder with that plugin in it. EG rename “post-credits” to “broken-post-credits”.
This will disable that plugin, and everything should work again (if that was the problem).
