I recently had to restore from a back up due to a faulty plugin, and now when I try to sign in to my admin panel I get an error 503, but the actual url of the website is still up and running and I can visit it. Do I need to disable everything, restore again, etc.
Thank you!
Start with deleting .htaccess file in your root directory.
If that does not work edit wp-config.php and enable debug mode, this might give you the error message.
If that does not work temporarily rename your plugins folder, if that works you will need to check each plugin that is causing the error.