Itunes says 12 GB of my phone is other; won't sync music onto my phone? (iphone 4)

So I update my phone with IOS 7.3 yesterday and I tried to sync it and it made me restore my phone (as usual). However, now when i tried to sync new music onto my phone, it deleted all my music and is telling me that 12GB of my phone is other. Now I don't have any music.

I still have all the apps and pictures etc. that I had before, it's just the music.

I've tried restoring it again but that didn't help. I also tried unchecking eveyrthing but that didnt work either. It just said more of my phone was taken up by other. I also tried restarting itunes but that didn't help.

So now that I've tried all of that, it says I have more music on my phone, which i don't, but also that I'm 10GB over capacity. Which is not true either.

Anyone have any solutions to this?