Resolved Please help: Romance Novel

Hello! Please help me look for this novel!
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It's a transmigration story. A female doctor transmigrated into a book after she died on a plane crash. She became an adopted daughter who was the book's villain. The original villainous adopted daughter was in love with the ML (who was betrothed to the eldest daughter of the girls' family) and considered her adoptive sister (book's FL) her rival; because of this, the adoptive daughter reached a miserable end. Therefore, FL was determined to save herself. She was good to her sister and wanted to avoid ML.

HOWEVER, differrent from the original plot, ML seemed to be in love with her. He considered FL to be his fiancé even if she was adopted because she was the eldest.

I can't remember much anymore, but the ending was that ML is a transmigrator too who knew the FL from the real world. He was her patient and he was in love with her. He became obsessed with looking for the FL when they couldn't find her body because of the plane crash.

Please help me. I can't remember the title. I couldn't find the novel either.

 

Perfect Fiance

 

THANK YOU VERY MUCH