Happiness is found inside yourself, not with someone else who has their own right to self determination.
So, knowing that she isn't interested in getting back with you, what are you prepared to do about you moving on and getting over her?
You do have some agency in this, you know?
Your ex doesn't seem consistently interested in anything further with you. Her "being all over you" isn't a contract for her loyalty and devotion. If your thinking is "if I let her in on the perks I'd give a girlfriend, I can convince her to be with me", stop. You can't machine a reaction out of someone who already knows they're not interested in going down that same path with you.
Your best course of action is to stop dealing with her until the best you can muster for her is indifference. You can't be her friend because you want to be her lover and she doesn't want you in the role, so what you do is to go "No Contact" (NC) and allow yourself the time and space to wean yourself off of her. You will never get to indifference if you keep contact with her or give her an avenue to reach you. That's not how healing and moving on works.
People treat you the way they feel about you
If you choose to remain with someone who doesn't treat you well, you cease being the victim and become the volunteer.
~Derrick Jaxn -- look him up