Restore from backup hell

Ooof, I somehow downloaded a copy of Catalina onto the same G-Drive that had my Time Machine backups on it. Now the drive is separated into G-Drive and G-Drive-data, and the only trace of the backups is a white sheet with the name of the backups, which also has a symbol that looks like the european road sign for ‘do not enter’. Disk utility shows 874 gigs of data as ‘other data’ but no idea how to access it. Last time I’ll blindly accept an upgrade from Apple. (The reason for the attempted re-load of Catalina is that after upgrading, and then buying a new Word subscription, GREAT, no word documents showed up on the computer for the period 2018 to the present. They also don’t seem to be in OneDrive, although I didn’t really know OneDrive existed until this am, when it was brought up by one of four Apple senior techs I’ve spoken to.) Presently, I have a 2014 MacBook Air with a brand new copy of Catalina, none of my data, and a G-Drive with, MAYBE, all my backups since 2014 locked up in it. NEED HELP!! Thanks all-