Oh wow. I am..like. going through the exact same thing. Except in my case, I'm "your ex." i broke up with a guy because I felt we should get to know each other better, but now he has found another girl, I try to be happy for them even if it hurts. I think you're right to feel the way you feel. She shouldn't be like that when she's your friend now. It's not what friends do. But my situation is a little complicated though, and I think i am in the platonic relationship as well with my ex....who likes another girl ._. argh. We just hold each other's hands when we're sad...But it's ending though. We're slowly on our way to becoming real friends.

Sorry for getting off-topic, but I guess what you should do now, is to tell your ex to bug off. Nicely. You are FRIENDS after all. What's the point in getting back into a relationship with her when you don't feel the same way for her anymore right? And I don't think you're ready for a romantic relationship either. Which by the by, you can take your time in doing so. The thing is to be honest as well, about your feelings for your ex and your current , well, closer than friends but less than lovers friend?