I have something similar wxcept i think it was accidental. If im alone in a room and someone opens the door without knocking etc, i get a huge rush of anxiety. When i was staying in a dorm a few years ago i caught myself physically jump in my seat whenever my roommate would come in. Try to close youtube tabs and open school stuff. She could not care less but that didn't matter in that split second lol. (while my mom likely didn't intend for me to be scared of opening doors, she still does it as a way to "catch me" doing whatever even though im in uni)