Handle With Linux

I can't imagine you messed up your configuration by following this. It seems like there is something wrong with your gdm or Xorg configuration. Start reading in /var/log/gdm/
/var/log/Xorg
/var/log/messages
if you see error messages in one of those files, search for those on google
It's probably something simple
try ctrl-alt-F8 to see error messages (ctrl-alt-F7 to get back)
Maybe a faulty /etc/X11/xorg.conf

see if there's a backup xorg.conf in /etc/X11

you can try to reconfigure x:

sudo dpkg-reconfigure xserver-xorg

If you really uninstalled your fglrx driver, I think you should reinstall it.
If you need a package manager on the command line try aptitude

seems like your user has a to low uid, see the security settings in the screenshot? Try lowering the minimal uid or even setting the allow system administrator login checkbutton

sudo aptitude install rungetty
sudo vi /etc/event.d/tty1
comment out "exec /sbin/getty 38400 tty1"
add line "exec /sbin/rungetty tty1 --autologin username"

using vi:

go to beginning of line you need to comment out:

"/exec"

type i

type #

use esc

type o

type:
exec /sbin/rungetty tty1 --autologin username

use esc button again

type:

:x

now when you restart you'll have a logged in shell on tty1 (ctrl-alt F1 to reach your tty1 1, ctrl-alt F7 to get back to the graphical screen)

OR

Edit /etc/gdm/gdm.conf

AutomaticLoginEnable=true

AutomaticLogin=username

For automatically logging in to the Desktop