She is young. Like any teen, she wants the freedom.
You're telling her you won't hold her back, but you care enough that it hurts you to see her wasting herself. And she's not completely defiant or closed to wanting to do things right. It sounds like she wants you to be really firm with her.
Ultimately, it comes down to what YOU want. Do you want to finish raising her and get her through high school, or do you want an end to the upset of her disobedience? I think the only way to overcome the negative feelings is to commit yourself to one course of action or the other.