Don't be "nice". Remember she dumped you. Keep your self respect and get some space from her. You need to get over her and let her go until you can even think about reconciling. You will try and talk yourself out of no contact but you have to be strong. I am now to the point (2.5 months later) where my ex and I are talking again and its from her end. Its amazing what time can do. We are friends and are happy where its at. Who knows what will happen but I am content with what it is now.
Stay strong man.