HELP :( grey songs cant be removed!

I used to remove music directly in my iPod (by swiping the music and then hitting delete) and when I connect it to my Mac, it re-downloads it again. Then the next day I wiped out my entire iTunes Library and extracted my music from my iPod and put it back to my iTunes Library and when I pressed "sync entire music library" the 221 songs that I DELETED from my iPod turned all grey and I can't remove it from my iPod nor via iTunes (because it's not visible there). I tried everything: syncing and re-syncing back, restoring my old iTunes library and syncing it back to my iPod, wiping out my music in my iPod, but the freaking grey songs are still there! PLEASE HELP 😟