Dead Flesh by T. W. Iain

Who is Rodin?
He thought he was a professional killer, paid for his expertise. But now, he no longer needs the money. He only kills to keep the nightmares at bay.
He thought he could remain detached. But removing those he knows to be innocent no longer makes sense. Tracking down a target on the whim of a vengeful old man and his conniving son makes him question his own motives.
He thought he only existed in the present. But everyone has a past.
The nightmares can only be held back for so long. Sooner or later, they must be faced.