iTunes not syncing to iPhone

My last sync REMOVED several songs and playlists from my iPhone. And I cannot seem to get them back. They are on iTunes on the laptop and it says it's syncing properly, but the playlists and songs are not showing up on iPhone. Sometimes they show up but appear grey and won't actually play. Some of them won't play and appear with a blue square surronded by a blue circle that does nothing if I click on it. Perhaps I need to call iTunes and get some help. This is VERY FRUSTRATING!!! I NEED these playlists to teach my fitness classes. Thanks, in advance, for any advice. I am desperate for help here.