Is this I Don't Want the Obsession of a Twisted Archduke...?
I reincarnated as the wife of a cursed archduke in my own twisted novel. As the author, I took responsibility and set things right by lifting the curse, which was the key to returning home. I thought my job was done, and just when I was finally trying to go back, the archduke asked me, "Did you really think I wouldn't know that you’re planning on returning to your fiance?" He had completely misunderstood! "Whether you like it or not, I'm still your husband. I'm never letting you go back to that bastard." All I want is for him to please let me go home!
In this Korean manhwa, an office worker is hit by a truck and wakes up in the world of a novel she'd written as Ridel Spencer, the illegitimate and abused daughter of a noble.
In the original plot of the novel, Ridel was forced to marry the Archduke of the North, Kyle Romani, who was afflicted with a 'Curse of Ice' by a blue dragon he killed. The curse caused his human emotions to be replaced by those of the dragon, froze anyone he touched, and killed him six months after marrying Ridel. She was then falsely accused of helping the main characters of the novel and executed.
This time, she decides to try and save both herself and Kyle by lifting his curse, hoping that this will allow her to return to the real world. Since she wrote the novel, she knows that the key to breaking Kyle's curse is a flower he keeps hidden on the fifth floor of his mansion. She also knows that Ridel has the power to reverse time on a small scale, allowing her to bring a trampled flower back to life.