The Rake's Secret Son: Harlequin comics

Helena marries the man she's always adored, the viscount Carleton. But her husband believes that their matrimony was all so that she could gain his fortune and he refuses to open his heart to her. He even goes so far as to declare that her son is no child of his and goes off to war, only to go missing. Everything after that is a living hell for Helena. Her husband's family treats her like a hussy, cuts her off. But seven years later, while she's been diligently raising her son, her husband suddenly shows up, ragged and on the verge of collapsing!