Seriously hacked – cannot even log into dshboard

Despite changing the user name and password after a previous haCk, my site has been hacked again and now I cannot even log in.

I see the message below when I type in https://www.andtewstucken.com/wp-admin

Is there any way of rescuing this?

And could there have been a back door from the previous hack they exploited?

“Warning: mysqli_real_connect(): The server requested authentication method unknown to the client [mysql_old_password] in /hermes/bosoraweb166/b1839/ipg.andrewstucken/andrewstucken/wp-includes/wp-db.php on line 1452 Warning: mysqli_real_connect(): (HY000/2054): The server requested authentication method unknown to the client in /hermes/bosoraweb166/b1839/ipg.andrewstucken/andrewstucken/wp-includes/wp-db.php on line 1452 Deprecated: mysql_connect(): The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead in /hermes/bosoraweb166/b1839/ipg.andrewstucken/andrewstucken/wp-includes/wp-db.php on line 1482”