Searching for a bl I forgot the name of

So there is this bl where the mc produces too much blood and donates it often. Also I think there is this rumor about vampires going around. One night the mc gets attacked by a vampire and drunken blood from. Turns out the vampire is his classmate who is overly relieved he didn't kill the mc. Because he is only half vampire he can only drink human blood and can't eat anything else. The mc decides to give him blood regularly because he has too much anyway. The parents of the ml are happy that this works because the ml had to sleep most of his life because of his condition. The dad is a vampire. The mom is human. Also the dad is an author.
Hope I can find it with this