Linked to PoE website w/steam and lost all of my characters

The Steam Account tool on the Manage Account page overwrites the data of any Steam Path of Exile account you have currently associated to your Steam credentials with what's on your standalone account.

If you can contact us at support@grindinggear.com with the email address associated to your Path of Exile account, we can look into restoring your accounts to how they were prior to being linked. :)