hi turq, long time no see. sounds like a complicated situation. jme, but can you detach yourself from roomie's issues/OCD,etc? it sounds like you feel you get sucked into her stuff. and yes that can be a trigger for depression, so detaching yourself emotionally would help...meaning, that stuff is on her. if you reward her behavior by letting her know it bothers you, it will only create more conlict for you. but then-the hard part-let it go. don't absorb the anger/frustration within yourself. if she won't speak to you, etc. ignore it and go on about your business. it's like giving her an audience if you don't.
sorry but glad i'm not in your shoes, but hope these suggestions may help you.