The Crimson Lady 

Karen Heyer thought that a happy ending with the male lead, Raymond Sayerteth, would help her escape the romance novel she had entered. Unfortunately, fate had other plans. Karen soon discovers that regardless of how the story ends, she always dies tragically and returns to when she was 17. After being forced to relive the story for 117 years, Karen's sanity finally reaches a breaking point... as she decides to change her destiny by killing everyone who has wronged her. (Source: Tapas) Note: Includes 10 extra chapters.