Transmigrating: Vicious Supporting Girl

*Bummer! She transmigrated into a chick-lit that she's been reading, but she's not the "Mary Sue" female lead with the aura of "everyone loves me, and I love everyone"! Instead, she was the most classic villain - the vicious supporting girl! What the hell?! 
So the plot of this book was: her fiancé fell in love with the female lead helplessly, all her sibling brothers alienated her but adore the female lead. So she picked on the female lead almost every day, but eventually everyone hated her and betrayed her, she became the most infamous girl in the city and in the end she died nowhere. 
She cursed in her heart: "what a shitty script for me! Okay that's enough I'm gonna shake off that damn fate by myself! "
"Since "Mary Sue" has to step on me to get to the top, don't blame me for being a villain to the end of her life! "
Let's see how she reveals the true hypocritical face of the female lead and changes the main characters' script! 
"But wait, why are all you male characters staring at me so horny?! I'm not the damn Mary Sue!"