IPhone 4s :: Duplicate Songs After Sync Making ITunes Slow

I have noticed that, after syncing, many of the songs on my phone have about 55 duplicates. None of these duplicates are on iTunes, and they don't appear in any of my playlists or albums, just in the Songs category on my phone. Instead of having around 1800 songs, I end up with 21 or 22,000 songs, mostly duplicates. I don't use iTunes Match or the Cloud. I can delete these duplicates, but there are way too many to do it manually, and they still appear in grey when I delete them. This is making the iTunes on my phone very slow.