I have a friend who has problems, as well as me. Recently we've fought and she told me to be nice to her, but for some reason i can't because i don't know how to be nice to people like her, but we're really good friends, she told me to say a few things and i have and i have started to slowly become nice to her, but now every time we talk she acts like i have to be nice to her and she is allowed to be mean to me, she always does it and every time i say something about it she will end up talking about her problems and it just makes me feel bad. I don't know what to do.