Back to the main plot, our mc is actually THE ghostwriter in the story he woke up to therefore he needed to change his ending. He decided to get a new job for the cat(of the ghostwriter) and himself . At his new job, he's an assistant to the gardener there and he did a bunch of good stuff. And one day, the duke/prince (I'm not sure about his position bye) there found his voice nice and heard he did good stuff so he decided to ask the mc to help him sleep at night.
maybe this? haven't read it since I'm waiting for the official to pile up.
https://www.mangago.me/read-manga/should_i_write_you_a_love_letter_instead/

I read it on another web (yes that one sigh) and I'm pretty sure it didn't get officially translated yet? It's also a novel. So basically the mc is working his ass off irl to try to pay back the debt his dad left. Before that, they actually had a pretty good relationship but it fell apart.
And there's a secret that he keeps to himself which is there's this manhwa or novel or whatever he likes to read.
So one day he actually fainted due to work exhaustion and that he found himself waking up as one of the characters in the manhwa. But the thing is the character that he became actually dies a horrible death.
To explain the story, the mc in that story is like some super beautiful person that even his family worships (if I'm not wrong) and there's this duke (I'm not sure if he's the duke) who has a reputation of being cold-hearted so the mc wanted to get through him. In order to do that, he hired a ghostwriter to write letters to the duke for him.