Are you sure you posted it in Fan Creations? There have been a lot of times when people have posted in the wrong sub-comm accidentally. Also, it sometimes takes like 2 minutes or so for a post to pop up if it's fairly large data wise, so try looking for it again it may pop up! Other than that look through your own 'profile page' (top right bit) and order the dropbar to 'Their Discussions', if you don't see it that way then sorry man it ain't there.
As a fellow absurdly long post creator, I've taken up the habit of saving a long post to notepad/word or other such thing before posting. Personally it's because of the dreaded 'backspace means back' mistake that some have fallen prey to, but I suggest to do that either way. Good luck!