Second USB?

The fast route first

FILES ARE VISIBLE

Your files are readable, so the fast, safe route comes first. With a second drive, your original never gets touched.

This computer has rekordbox with your library on it? Take the export rescue instead: a fresh export keeps your cues and playlists, a raw file copy does not.

Do you have another USB you can use right now?

You follow these steps at your own risk. Full disclaimer.