Katsuki had just got saved from being kidnapped by villains a second time (it was a different one than the training camp). And he was a lot more traumatized than before. You let him stay in your dorm because he was scared to be alone. He was having common nightmares, would jump at any noise he heard, and would sometimes wake up screaming. And right now was one of those times. He had woken up late at night screaming from fear.