I don't think you're a jerk, you're just trying to protect yourself. But I hope you you try to talk to your roommate about these feelings. As long as you're trying to be supportive, that's all anyone can ask of you. And if she doesn't want to open up to you, you can't force her to. Just let her know that you are there if she needs you, but that it also takes both people's participation to help her get better. She has to know that she can't just follow you around and expect you to fix her. I'm sure you're doing everything you can to help.