Can't connect to database from virtual host, please help

Hello,

I've been running my Drupal website in the localhost through out all the development phase.

Now I need to move the site from the localhost to a virtual host I created with Apache. However, I'm having some problems.

The first thing I did, was to change the $db_url in my settings.php file and configure phpmyadmin accordingly, but whenever I try to access my site, the page "Unable to connect to database server" appears. Inside that page, it says: "The MySQL error was: Access denied for user 'username'@'localhost' (using password: YES)."

Shouldn't it say "MyVirtualHost" instead of "locahost" since I changed it in the settings.php file?

Well, I decided to change it back to "localhost" from "MyVirtualHost" and try again. Now, the frontpage is accessible, but any page inside it throws an "error 404" page.

I'm really desperate about this issue, could your guys help me, please?