"icloud drive is loading..."

I've hit a wall with my ability to understand how iCloud functions.

I use Procreate and have been trying to move files out of Procreate to iCloud Drive for backup.

I had Procreate taking up ~17gig of my 32gig iPad, I was able to backup many artworks to iCloud via the Files App. They're accessible online from a PC, so the backups worked. Except now the Files App on my iPad reads as taking up 5gig of storage space, while Procreate has come down to 12gig. 12gig plus 5gig is the same as the original 17gig Procreate was taking up. So I haven't cleared any space at all. Now my iPad is screaming at me that it's full and iCloud is no longer loading, it's just stuck at "iCloud Drive is loading..." forever. It's been stuck on that for as long as it took me to write this post.

How can I remove the backed up artworks from Files? And how can I connect to iCloud Drive again?

None of this should be taking days to get done. It's backing up work.