First of all, english isn’t my first language so i'm sorry for any mistakes. Now about the manhwa, i don’t remember the main couple (straight romance), but i think the mc reincarnated towards the end of the novel. The things i remember from it was the other couple's context: the crown prince (black hair, golden eyes?) was engaged to a saintess (pink haired?) from a commoner background, they were the main couple in the novel mc reincarnated in. The saintess becomes a villainess and they divorce. I think cp dad's was sick and saintess didn’t cure him.
The fl (reincarnated, i think she has light brown hair but i'm not sure) got engaged to the ml (white haired) as a child, she stops his mother’s(?) abuse against him and they grow closer. She still thinks the plot is going and that he is going to fall for ogfl (blue haired). OgFl is artistic and fl supports her. Ml was jealous of ogfl cause fl was giving her too much attention and fl was jealous of ml because she thought the original plot was happening m. Sorry for the bad english, someone please help me find it