Truly, Madly, Deadly by Hannah Jayne

Every relationship has its secrets and Sawyer's dies alongside her perfect boyfriend. They said it was an accident… it wasn't. An exhilarating thriller, Truly, Madly, Deadly will leave readers chilled to the core. Sawyer Dodd had it all: perfect grades, star position on the team, and the perfect boyfriend. But when Kevin dies suddenly in a car accident, Sawyer is stunned. Until she opens her locker and finds the note:You're welcome. Someone saw what he did to her. Someone knew that Sawyer and Kevin weren't a perfect couple. And that someone will do anything to protect Sawyer.