Itunes decided to create a new playlist...

Hello,

So I started my Itunes like I normally do. when it loaded a box appeared only giving me too options which was making a new playlist or quit. I tryed many times clicking quit but it ended up closing the program. So I was forced to create a new playlist.
The question is: If I sync the ipod will it erase the applications since it says it will erase everyithing on the ipod so i was just wondering if anyone can help or give tips on how to get the other library back?

Thanks :)