book where the main character is struggling with a behavioural addiction

For my sociology of addictions class i have to do a book report on a novel (preferably fiction) where the main character is struggling with a behavioural addiction. NOT drug or alcohol addiction. internet addiction, relationship or porn addiction, shopping addiction, video game addiction, or food addiction are my main options. it cannot be a self-help book.

note: i was originally thinking of using the book “Confessions of a Shopaholic” by Sophia Kinsella but my professor said it covers addiction in a “fluffy” way which can lead to limitations in terms of the assignment.

by alyyyyssa113