Copy playlist and tracks from folder to new USB

Hi!

I recently lost my USB drive. I regularly would copy the entire USB to a folder on my mac. I used to be able to just copy the entire folder onto a new USB with the same name and all my tracks and playlists would be backed up without a problem.

This dosen't seem to be working anymore. What has changed? How can I get my music and more importantly my playlists back?

It took me YEARS to organize the music in the right playlists. I'm dealing with over 16 000 songs. There must be an easier way.