While they are apart, Tessa begins working at a restaurant with Landon, and Hardin begins attending Alcoholics Anonymous upon graduating from university. When Hardin visits New York, he and Tessa slowly reconnect, but when Tessa discovers a manuscript about their relationship in Hardin’s belongings, she becomes upset and ends their relationship.

After the book’s publication, she attends one of Hardin’s book signings but doesn’t approach him after misinterpreting a glance between Hardin and a woman in the crowd.

Source: https://www.distractify.com/p/do-tessa-and-hardin-end-up-together