Sync problems with iOS 8.4 - iPhone won't accept new media or changes from iTunes
After updating to iOS 8.4, I've encountered a problem. My phone still reacts when connected to iTunes, I can add new podcasts, videos and music - new apps, changes in playlists. And when I press "sync" it seems that all is well, but when I look at my phone afterwards, I can see that no changes have actually been applied.
I have Vista (I know, it is the worst), so I can't update iTunes to 12.2, so maybe that's part of the problem. But they can't seriously expect me to buy a new computer, just so I can put new music on my phone?
I have tried re-installing iTunes, restarting computer and phone.
Can someone please help me?
(On a (somewhat) unrelated note, all my album art has disappeared, too.)
iOS 8.4