Don't give up, everything is always solvable
Can you post you /etc/apt/sources.list ?
I think your problem may be that you have got some sarge repositories and some etch repositories, so apt doesn't know what to do.
Try commenting out any sarge repositories, and run "apt-get update" and then try installing X again. This way, the X server will be installed from the testing repos. Alternatively, comment the testing repos and install the X server from sarge.
I hope this helps
--Ian