All music from Apple Music playlists and library have disappeared

I have an iOS and all my music in playlists and library are gone. i turned on sync library but nothing happened. it has happened to me many times in the past but after turning on sync library, it would fix. but this time it didnt. playlists are there but no songs.

[Re-Titled by Moderator]

Original Title: All songs are gone. Sync library not working.