The Queen of Everything by Deb Caletti
Published by Scholastic

Set in America, this is the story of high school student Jordan Mackenzie.   For the first time in her life she feels she is living as normal a life as possible living with her dad after spending years with her hippie mother.   But things start to fall apart when her dad starts dating a married woman, Gayle D'Angelo.   As her dad's affair spirals out of control, Jordan tries to make her dad see that he is not only destroying his life, but the lives of all those around him.   In the end, this story finishes with a dramatic climax and Jordan trying to pick up the pieces of her life.