Here, in My Head — Lauren Stone

At the age of sixteen, Sam has already found the answers to who she is, and takes pride in that. But when Alice walks into her world, and turns it upside down from day one, she starts to learn that things aren't always black and white. Together, they embark on a journey of self-discovery the likes of which Sam never dreamed imaginable.. The lessons that Alice teaches are not pleasant, though, and Sam will have to find a way to see past them, because she is to find out that disembarking is not the end, and it does not always promise happily-ever-after. Disembarking means the finality of one journey, of answered questions, and the beginning of a new journey, a new embarking.