Horegusuri Event ga Watashi no Okite Shimaimashita

The twenty-year-old girl thought her bedridden life had ended. But the next moment, she was reincarnated as Renese, the villainess in her favorite R-rated romance novel. In the novel, the heroine, Aria, and the hero, Prince Frantz have a fateful encounter and fall for each other. Frantz's fiancee, Renese, tries to break them up by using Elden, her knight. Elden is also in love with Aria and betrays Renese in the end. She decides to change the story this time so that Elden, her favorite character, can be together with Aria. First, she must avoid the "love potion event" which happened when Aria accidentally spilled a love potion on Frantz. However, the potion was spilled over Elden! And somehow he starts pursuing Renese passionately...?! (Source: MangaPlaza)