My Ipod Nano doesnt sync anymore.?

My Ipod Nano doesnt sync anymore? I formatted my ipod not via the iTunes but via the My Computer and G drive like a USB pathway. After doing doing that, all was left of my ipod was language. I downloaded updater on iTunes and somehow the other features came back. But when I tried syncing it with iTunes, the songs wouldnt show when I play my ipod. At first try I restored my Ipod to original factory settings and uninstalling iTunes but then nothing still happened. What should I do????