Entering into a serious relationship takes a lot of efforts. To name a few: 1. to respect your partner and to minimize any potential misunderstanding, cut all ties with your ex, no matter how much you cared and loved him and her; 2. to avoid hurting his or her feeling, drop all stories with your ex, no matter how sweet they were; 3. to show your appreciation and love to her or him, introduce her or him to your friends (there shouldn't be any barrier to do so if you care and love your partner). You certainly shouldn't feel ashamed to be his gf or her bf --- (it seems that these three are derived from your description, but there are the fundamentals to a healthy and happy relationship.)
Based on the above mentioned criteria, I have reached the following conclusion: dump her as soon as you can = right now (if you haven't done so yesterday). Clearly she doesn't give a shit about you, so why would you stick around, huh?