Apple Music duplicated my entire song library

I have over 5,000 songs, built up over the last 15 years. Apple has duplicated every single song, keeps creating duplicates of my playlist randomly. I use a Mac, Macbook and iPhone and use sync across all three (which was always the major benefit of iTunes). To remove them I have to go to File>Library>Show Duplicate Items and Click every second (duplicated) song: that's over 5,000 clicks! I don't want to pay for a third party tool (which might mess up my library even more than Apple has messed it up already). Any ideas?