Very Le Freak by Rachel Cohn
Very (Veronica) has always been a “love ‘em and leave ‘em” kind of gal. She is also techno-obsessed. She is always plotting a playlist based on what is happening to her at any moment. So far, her roommate has not just put up with her, but helped her out of problematic situations, until she not only ditches her best friend after having sex, but to show that they have really broken up, she goes down on him while (unknowing to her) her roommate watches.
There is an intervention, and Very is forced to a 12-step techno camp.
As with other Cohn books, we love the heroine, and will only find her in a public library…