With error message the is no access on file system layer anymore. There is no mount, umount or fsck.whatsoever! Try to copy the partition table back with the dd command i pm'ed to you to get it, hopefully, working. Or, in some cases, you could try to recover files with testdisk and then reformat the file system.
sudo gainroot dd if=/dev/mmcblk0p1 of=/dev/mmcblk0p1 bs=512 count=1 skip=6 fsck -af /dev/mmcblk0p1 fsck -r /dev/mmcblk0p1 mount /dev/mmcblk0p1 /home/user/MyDocs