I'm at a loss for what more to suggest. If you have recently backed up the library to the SD card or online, you should be fine.... otherwise, I'm not sure.

Does the EE give any indication of what it is doing at this point (eg, rebooting, migrating the library, purposefully trying to freak you out, etc.)? Did you format the SD card prior to inserting it? Just some thoughts...

Again, good luck. I hope someone else can give you some better/more info than I did.