Error establishing a database connection

My site was hacked and the vandals changed my WP login name and password. I could still get in to the site cPanel so I followed the instructions I found on the net and changed my username and password to something brand new using phpMyAdmin.

I then went to my wp-config.php file and changed the username and password to the new one I set up in the database. Now i get Error establishing a database connection.

I have looked at other threads but nothing really helping. Here is some more detail of what I did.

Login to phpMyadmin
went to mysite_wrdp2 sql database (the one for this site)
went to wp-users
found my only user account and went to “edit”
changed the user_login to “newname”
changed the user_pass to “newpass”
hit go.

downloaded current wp-config.php from site with filezilla
opened wp-config.php
changed the username to “newname”
changed the user_pass to “newpass”
uploaded wp-config.php to site root folder to overwrite old one.

= Error establishing a database connection.

Can’t work out which part I did wrong?

Please help.