Two by two / Nicholas Sparks.

"At 32, Russell Green has it all: a stunning wife, a lovable six year-old daughter, a successful career as an advertising executive and an expansive home. He is living the dream, and his marriage to the bewitching Vivian is the center of that. But underneath the shiny surface of this perfect existence, fault lines are beginning to appear, and no one is more surprised than Russ when he finds every aspect of the life he took for granted turned upside down. In a matter of months, Russ finds himself without a job or wife, caring for his young daughter, and struggling to adapt to a new and baffling reality. Throwing himself into the wilderness of single parenting, Russ embarks on a journey at once terrifying and rewarding-- one that will test his abilities and his emotional resources beyond anything he ever imagined"--Goodreads.com.