The answer to this depends wholly on what it is that makes her psycho, so I will give you multiple answers. If it is something simple that you can live with I would say just ignore it. If you are comfortable talking to this person (or arent afraid to) just tell them what is bothering you. Now if you can’t talk to this person and you really cannot handle living with them talk to a resident advisor to try to get your room switched. Or if you are in an apartment tell your roommate that you plan on moving with the lease is up, hopefully you aren’t in a long term contract. If they get upset about you leaving just tell them it is your life and you are free to live where you want. Now if for whatever reason you can’t change your living situation and you can’t talk to your roommate (or you have and they wont listen) then the best thing I can say is try to avoid them. If they are in the room a lot, just spend your time in the library or at a friends [if you are in an apartment then I would say feel free to lock yourself in your room]. It may make things a little weird, but it’s better than dealing with a crazy person, right?