Oof, sorry to hear it. Been there. In the future, be sure to click the "Backup Settings" button to the right of the "New Character" button (for client settings), and to the right of your character's name (for character settings). Worked for me last time I needed it, anyway.
If I have to backup my settings I always use the backup feature in the character screen and to be 100% safe, I duplicate the character folders where all settings are locally stored.