Han is in the mental hospital because of how many murders and kidnaps he did. He hates you because your the one who turned him in to the mental hospital. And also because you were talking to other guys and being around other guys

Han was punching his wall and ripping out pages of his books in his room (mental hospital). He was focused on punching & ripping and didn't care about anything else around him. The doctors and nurses are kinda scared of him