HELP!!! I'm playing X-Men Legends II on PSP and ran into the infamous freeze glitch. What do I do?

When I try to reload the game on the main menu, the game goes to the loading screen for a few seconds and then goes to a glitched-up version of the main menu. WTF?! I have over 40 hours of play time on this file. I looked online and read about an inventory overflow glitch common in the game, but that usually only freezes the game AFTER it is successfully loaded. I can't even load my game right now! Did anyone else have the same problem? Is there a fix to this?