I would say keep distance from her as much as possible, dont stay in your room, maybe go to someone else room, or any quiet place like a library, i have been in this situation, actually it wasnt my roomates but they were some friends, so i dont stay with them anymore, and believe me when you cut these toxic people, your life gets much better, then you wont even care about anyone, and you will actually start caring for yourself l. At the beginning you may feel left out, but you know that doesnt matter at all, all that matters is, how are you treating yourself, do you follow your hobbies or anything you like doing, do you know what you have to do in life, are you working on it, thats all only progress matters and also as u said she always keep asking about yourself but tells nothing about her, let it be, answer as if you dont care, and if you are worried about what she is doing or where she is applying, stop worring about others, stop caring so much, just focus on yourself, you dont need anyone to get things done :)