Database error - Site down

My website ( has been down the past couple of days and I keep getting this error message. I've tried creating new users in MySQL database and changing the  wp-config.php file to match. Still the same error. It's also in the front end and back end of the website.


I also tried uploading a new wordpress file and replacing the files via FTP except wp-content, and still got the error. I'm at a loss for what to do now. Any ideas?