Such a cute contemporary fiction way backlist title (1997). Some quotes in the movie based on it (Someone Like You, an old fave) were pulled directly from the book, but the ending was quite different.
Jane works in talent booking at a TV talk show. She starts a steamy affair with a coworker, but when it goes belly up, she loses her apartment and becomes roommates with a womanizer. She starts developing funny, unhinged theories based on these men.