Amber, if the Apple utility can't access your card to repair your card. try the following:
I'm not sure if it is the same in a Mac as a PC, but if there is an option to do a "quick" format vs. a "regular" format, try doing the "quick" format. The reason is a "quick" format will just overwrite the file allocation table (FAT), the partition on the drive (card) that indexes the files and leaves the actual files untouched, whereas the regular or destructive format actually overwrites the file storage area.
Obviously, if you want to try to repair or recover any files on your card, you want to leave the files themselves untouched and not overwrite them during a formatting operation.
Hope this helps.