iOS 8.4 update has replaced my album artwork and deleted my playlists

Really hope someone here can help me out because this problem has been driving me insane and I can't see how to fix it.

Ever since I updated my iPhone 6 to iOS 8.4 my iTunes has been totally messed up - half my album artwork has been replaced with random stuff (some not even relating to the artist in question), all my playlists have been deleted and some songs are only playing ha;f way through before jumping to the next track.

When this has happened before I've just been able to remove album artwork and then restore it, but as Apple love to complicate things I can't see how to do this with the new edition iTunes on windows (which I hate, for what it's worth).

Anyone else having these issues, and if so, have they got a fix? I know it's not a major fault but it is incredibly annoying and playing havoc with my OCD.