I don't think I would have been able to get to sleep without getting this figured out.
I decided to have my computer show the hidden files. There was a hidden file for adobe digital editions, but when I tried deleting it, it said it could not be deleted as it was a corrupted file. I couldn't open it, or do anything with it. So I went over to the internal memory and found the adobe file there, copied it to my card, and then I was able to delete the corrupted file. I disconnected from the computer, and suddenly all my books showed up! So somehow that corrupted file was making everything hide.
Ok, now I can go to sleep.
