For getting back X, you need to reconfigure it. No need to reinstall anything.
Have you tried executing either of these commands from the console as a root user?
You should run the first one if you still are on XFree86 and you should run the second if you're using Xorg. Most likely you'll be using Xorg. Try either and see which command exists on your system.
Once you configure it. Log in as a regular user and then type
to get into your GUI mode.