The Fight and Flight of the Sickly Villainess

After living a life of as a corporate slave in Japan, she had reincarnated as a villainess, Fiona, into an otome-game. When she saw her identity, she decided to live a happy slow-life as a noble lady. It'd be lucky that her fiance, Louis, wishes to call off their engagement.
However, she soon realized why Fiona had to act like a villainess. She was sick and had a difficult time living as a normal noble lady.
Since she'd like to live a happy life (alone), she started to change her food, life. and be honest with everyone. Then...something she'd never expected happened.
Louis started to say that he loves her so much and never wants to break the engagement! What's happening? It's too different from the original game!
Why is he so sweet...?!?!