Hello

I am having a hard time with getting music on my lumia 822. I try and use the windows phone desktop app so it will sync with my iTunes, but it keeps closing after like 30 minutes with less than half of my songs synced. And what makes it bad is that when I open it back up it starts to sync from the beginning of the songs, instead of picking up where it left off. Is there something im doing wrong? should I just sync a little at a time? please help

I really need help, I am so frustrated, I bought a windows phone for all its amazing features, but if I can have my music, it will be returned soon.