iPod Touch 4th gen version 4.3.3 won't sync to iTunes and won't open my apps

I have an iTouch 4g. It isn't jail broken and is in a perfect condition but when I was about to put new songs, it wouldn't sync into my iTunes in my laptop. I disregarded it thinking that it will be okay after a few days. I'm not usually using my iPod for games, I usually use it for reading (iBooks), taking notes, and listening to music. After 2 days, i tried using iBooks and it wouldn't open. I found out that all the apps i downloaded wouldn't open too. I tried syncing it again but still, it says "The iPod 'Czelene's iTouch' cannot be synced. An error unknown occured (13019)"

Please help me. I badly want my iTouch to be fixed withouth missing anything in it. 😟