Dreamland by Sarah Dessen

Ever since she started going out with Rogerson Biscoe, Caitlin seems to have fallen into a semiconscious dreamland where nothing is quite real. Rogerson is different from anyone Caitlin has ever known. He’s magnetic. He’s compelling. He’s dangerous. Being with him makes Caitlin forget about everything else–her missing sister, her withdrawn mother, her lackluster life. But what happens when being with Rogerson becomes a larger problem than being without him?