/etc/fstab is messed up somehow. You need to look at it and figure out what's wrong and fix whatever is causing the error. It's probably simplest to do this by booting a live CD and mounting / on your normal boot device. It's been a while since I did this to myself, but IIRC I followed the instructions you show, giving it the right fstype:device argument. Then I changed / from read-only to read-write by mount -urw /.
