Syncing Itunes to Galaxy-Lost music

Hello people.

I am feel like a Jerk as I am very computer illiterate and have nothing to offer you fine people, however I am needing a bit of help.

I recently purchased a samsung Galaxy and have attempted to sync my itunes library with my galaxy using the "mywalkmanitunes" or something like that.

Now, Itunes cannot find any of my music.

I humbly ask for your help.