Good suggestion. Keep your door closed and locked. Keep your keys and a jacket by the door, ready to grab. If the chronic complainer knocks, grab your stuff and say that you were just heading out—to see an instructor, to the library, to do some research— some place he won’t want to tag along. If he says he needs to talk, say you understand and recommend that he talk to the chaplain or other local religious leader. Send him to his counselor or dean or campus health; it doesn’t matter because you sympathize but you have nothing else to offer.

In actuality, this is a good opportunity for you to develop such techniques as there are always people who talk ad nauseum about their problems. They don’t care to whom they talk because they do not take any actions to resolve their problems. I don’t know if the talking makes them feel important or what, but once you become unavailable, they will find some other set of ears.