Have you installed any mods recently? My guess is that there is a misplaced or corrupt file that's preventing the game from properly loading up. Changing your rendering subsystem might help to solve this as well. You can do that by going into your Feral Heart folder and opening the file named Settings in the notepad format and changing the system directly from there.For more help you may want to refer to Moon's Feral Heart Crashing guide here: http://www.feral-heart.com/smf/index.php?topic=57629.0
I'd suggest taking a look in your particles folder, look for duplicates. If there are any files in there ending with _0, _1, etc, delete them. These pesky extra particles can cause FH to crash as you described.