The message below comes from another post and I tried it the way that they stated to. First, I mounted the USB drive:
sudo mount -o ro,noexec /dev/sdb1 /media
I mounted it as read-only to prevent any damage or changes to the USB while copying it, especially if I mixed up
of. In the message below, I'm not sure if they wanted to me to use
Before trying any recovery I would save the current state by backing up the whole device block by block:
dd if=/dev/sdb bs=16M of=/somelargedisk/rawusbdrivewhere /dev/sdb is your USB drive (check which one by using lsblk) and /somelargedisk/rawusbdrive is a path and filename you choose on a disk/partition with lots of space. Then, if a recovery tool that writes to the disk makes more damage than repairing, you can go back (exchange if and of fields)."