I think you need to re-evaluate exactly what you can realistically expect from this relationship. Three important factors in a romantic relationship are: friendship, commitment, and a shared meaning in life. FRIENDSHIP is based on mutual trust, understanding and empathy for each other. Do you honestly have this with her? Do you feel like she is trustworthy? Does she understand you? The factors of commitment and a shared meaning in life are obviously not there. So what are you getting from this relationship? Is it possible that you are infatuated by her? Give yourself a reality check and ask yourself: Is she really the kind of person you would like as a partner? Does she make you feel loved and secure? Are you denying the reality and living with an unrealistic view of this relationship? Be objective, not emotional when you answer these questions. Since writing makes you feel better, write down the answers.
It seems like the bottom line here is that she doesn’t want a committed relationship with you. Rather than holding onto false hopes, it may be best to let go of this relationship, and focus on living your life in a way that gives you meaning and purpose.