I think there is more to Lizzy’s turmoil than the discovery Wickham is indeed mercenary and the fact Darcy loved her is a surprise but I do not think is has lasting shock value in itself nor to Lizzy the most important discovery. The most important discovery to Lizzy is how seriously she misjudged both men. Her ability to judge people’s characters failed her greatly with regards to both Darcy and Wickham. She let her correct initial impressions of Darcy, that he is a disagreeable ill-mannered fellow; lead her to believe he was also a dishonorable man. She let Wickham’s agreeable gentlemanlike manners lead her to believe he was a good honorable man despite the obvious discrepancies between his words and his actions. Lizzy’s pride is wounded because she misjudged so badly and she is ashamed that she let her prejudices sway her into recommending Wickham’s side of the story and accusing Darcy, an honorable man, of dishonorable acts. I think self-realization and reevaluation can be an extremely emotional experience whether you are a regency lady or a modern one. ;D