What can I do about my roommate's drinking problem?

My roommate has had a drinking problem for a while. She goes out, gets trashed, and then expects everyone to take care of her. The next morning, she apologizes constantly until she feels validated. She also thinks everyone hates her all the time. If I don't seem anything other than happy, she asks me "Do you hate me? You hate me. Tell me you love me," and I feel like I have to pity her because she has also been suicidal before.