Mind-aches are the worst of all
She turned alternately pale and red, pale and red all over, again and again, as the thought grew up in her—and soon the growing thought became a torment. This new-born feeling of shame was unendurable—its birth a travail that racked and rent every fibre of her moral being, and she suffered agonies beyond anything she had ever felt in her life. (…) And Trilby, as she lay disconsolate on her bed all that day and all the next, and all the next again, thought of her past life with agonies of shame and remorse that made the pain in her eyes seem as a light and welcome relief. For it came, and tortured worse and lasted longer than it had ever done before. But she soon found, to her miserable bewilderment, that mind-aches are the worst of all.
– From Trilby (Du Maurier, George)