It's clear that this is a first work. It's kind of written "fanfic style", like 50 shades. I think the author is too preoccupied with the couple getting together and there being excitement that they forget to give the story a natural flow.
How is it unrealistic?
The disorder? It's real and sometimes it can appear with no warning, often it is either genetic or due to head trauma.
The forwardness of the past relationship and confession? Well, it has been months since they met and he was first thought of a weirdo and only when he sought to talk to him during camp did they bridge a gap into friends. He probably feels he needs to be forward.
The fight? Bai was angry that after all those months of being friends he was never told about this big thing. It made him feel that he was the only one who thought them friends. Plus, Bai has feelings for him even if he is unaware of it. Which is why was so dramatic about things because it hurt him and he didn't know why.
the art style is so cute but it's unfortunate that the story is so unrealistic and cliche. it's just unbelievably melodramatic. I can deal with some drama for the sake of the story but this is just too unrealistic. it's too bad since the character design is so good, i'll keep reading for the cute art but I wish the story was better. i'm getting tired of badly written BL cliches honestly, it's annoying and frustrating to see characters acting so senselessly.