MySQL not working

[TheLG]

Hello, I am now on this forum and I need help with my MySQL Server which is on my VPS with Ubuntu 12.10 Server.

Everything was fine 'till today, when I tried to login to PhpMyAdmin (as root) and I got theese two errors:

#2002 Cannot log in to the MySQL server
Connection for controluser as defined in your configuration failed

So I googled for the solution, found something and commented theese lines in phpmyadmin config:

$cfg['Servers']['$i']['controluser'] and $cfg['Servers']['$']['controlpass']

Now the error I was getting changed to

#2003 Cannot log in to the MySQL server

So I tried to access mysql from my VNC Client, I logged in as root and typed

$ mysql

and I got this error:

Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)

I checked and I couldn't find that file!
I tried creating it with touch, but didn't work..

Then I tried to start/restart mysql service but when I type service mysql stop/start/restart I get:

Job failed to start!

I also tried reinstalling mysql, php and apache2 and nothing worked!!
Please help me, my MC servers can't work without MySQL!

P.S.
Today I changed ServerName in apache config because I was getting an error when I typed service apache restart:

Could not reliably determine the server’s fully qualified domain name, using 127.0.1.1 for ServerName

I'm not sure does that have anything to do with my MySQL problem.

And there is one little thing I did in sudoers (by typing visudo):
I wanted to execute commands from php as root so I added this line at the end of the file:

www-data ALL=NOPASSWD: ALL

Unfortunately, it didn't work so I removed that line..

Please help A.S.A.P.!

Thank you very much,
Leon Grdic