This looks like a Wubi install, and likely you had NTFS filesystem corruption, perhaps due to a hard shutdown? or some other crash. In any event, running
boot-repair on Wubi installs is not a good idea... because it's not written by someone familiar with how Wubi works.
What you should do on a Wubi install is first run
chkdsk from Windows, because the host filesystem is often what is corrupted, and only then, if necessary,
fsck the root.disk.
boot-repair will always offer to
fsck the root.disk and this can result in a catastrophic loss. Right now it's reported a zero file size.
So, you should run
chkdsk /r on the host drive and see if you have an intact
\ubuntu\disks\root.disk. Otherwise it's probably damaged beyond repair.