I would reccomend a boot into runlevel 1
at the boot: prompt, simply type
This will get you into a CLI
edit your /etc/inittab default runlevel, and set it to 3 (what I mean is, there might be a line like this:
change the 5 to a 3
This should get you to at least a CLI, where we can troubleshot the X issue if there is one.
reply when you've done that or when/if you need help or if it doesnt work