I am not used to fedora, so take this advice carefully (mostly with regards to choosing the right runlevel):
You could stop X starting at boot by booting to runlevel3 in most distros (not debian or (k)ubuntu)
See /etc/inittab and change the default runlevel from 5 to 3 (maybe different for fedora?) and reboot.
Probably easier though (and no reboots): in a proper terminal (<CRTL><ALT><F1>) login as yourself.
su - to root then just
X will be shut down.
exit so you are back as yourself.
Then you can startx with any parameters you wish, and see any messages in the terminal.
The X environment is usually to be found on virtual TTY 7
<CRTL><ALT><F7> to switch to it, and <CRTL><ALT><F1> to switch back.
Of course you can also access the other terminals with <CRTL><ALT><F2-6>
When messing with this sort of thing I usually have
<CRTL><ALT><F1> running as myself
<CRTL><ALT><F2> running as root
<CRTL><ALT><F7> my X display (or not, depending).
Once you have it sorted, just reboot, or init 5 as root
X generally logs the startup events, and warnings / errors to /var/log/Xorg.0.log
That file is worth looking at.
There's no need for auto-flagellation.