This is Not a Love Letter by Kim Purcell
Jessie and Chris are taking a one-week break to get some perspective before graduation and the big, scary decisions about their future. Then, Chris vanishes; the police think he’s run away. He was about to head off to college on a full-ride baseball scholarship. And he disappeared on a run along the river– where some boys from the rival high school beat him up just three weeks ago. As Jessie searches for answers, she must face her fears, her guilt, and a past more complicated than she would like to admit.