Just updated my iTunes and my 10 year collection of music is destroyed . Is there a way out of this ?

I clicked "update" on my I phone 6 to get the latest iTunes, and to my horror my music collection appears to have been destroyed. I cannot edit my play lists in an order that I want, when I move a track to s specific spot on the playlist when I click done the order changes even songs that I haven't moved move. This is a disaster for me! I cannot seem to access my playlists when I put my phone in aeroplane mode either. Is there a way of reverting to the previous edition, which was very easy, convenient and simple to use?