Entire "Users" folder is missing when booted into Recovery Mode
This is normal.  When you boot in to Recovery, whether it be from your local drive or via the Internet, you’re booting a completely different instance of macOS.  

If you want to view the /Users directory, you’ll first have to mount the internal drive to a directory (i.e. /Volumes) then you can navigate to it.

As for corruption of your drive, it is better to get an enclosure or a USB to SATA adapter, mount it on a “full blown” version of macOS so you can make an image of the drive and work off of that rather than risk further data loss.