Basically to put it in short, MC is losing his identity when he transmigrated to the novel. It caused him a lot of stress because the world is forcing him to accept that he is now Seungwon. Seungwon character is quite pitiful and doesn't have a good ending as a side char which made it worse. MC is refusing this and constantly having anxiety. His actual lives always played in his memories quite randomly. It's also causing his mental health to deteriorate in the novel because it's like him having split personality if we want to understand it as a reader. That's why it's confusing for us. One moment he's telling the story as Seo Seungwon. Then just like a switch, when he is trigged or he remembers, he will tell the story as a person who has transmigrated with an actual original memory outside the novel
Okay, thanks for the explanation, but i think I'm gonna drop this one...
I don't understand a single thing in this manhwa, help...