From looking at the original post, the file-system went into read-only mode. Which means there is probably some problem with your HDD/SSD - possibly some bad sectors, or some other problem that indicates that the disk may be close to failure. Or it could just be some corruption of the file-system.
So, your first port of call should probably be to boot a Linux live USB, or liveCD/DVD and try to recover any data/files from your drive, then run fsck on the HDD/SSD to check the integrity of the file-system and the disk.