The Darkest Corners by Sydney Jamesson

After surviving a life changing event, celebrated artist Maxwell Grant has not touched a paintbrush or a woman in four years. During that time, he has tormented himself over an unspeakable act he dare not admit to, even to himself.
His one chance at redemption comes through a journal left behind by Harriet Harper, a mysterious woman in his night school class.
Shocked by what he reads about her tortured existence, he becomes obsessed by her and falls headfirst into a dangerous game of he said, she said, not knowing who to believe—who to trust.
When a dangerous character from Harriet’s past appears, events take a turn for the worse and he must say and do whatever necessary to save his sanity and, more importantly, his four year old daughter, Poppy.
Some secrets never get to see the light of day; others are just waiting to be uncovered … with shocking consequences.