Itunes 12.4.3.1 update

Ever since I updated my Itunes to 12.4.3.1 all of my playlists have disappeared and I cannot find them anywhere. They have literally been deleted and I don't know why or how because this suddenly happened as soon as I updated. The songs are still in my Itunes - media folder so I'm really frustrated because I can't figure it out. I haven't been updating my songs since Feb because at first I got lazy and after the update, I can't find the playlists to update the songs into! Does anyone else have this problem??