I felt for you and your rush experience. I have two daughters and the same thing happened to one of them. She did decide to rush a second time and the same thing happened again. We will never really know what happened but I believe it was because she is a little reserved and not a party girl. The one young lady's post - addressed that being too much of a partier can be negative but the other may also be true. It was especially painful because she was a legacy through me and her aunts. I trusted that the rules of my day would benefit her, but on her campus legacies were not valued.
My sorority life made my collegiate experience very special but the events with my daughter have changed the way I now feel about my affiliation. I will never feel the same way because of the heartache associated with her rejection. I did not want my second daughter to rush but she was determined and it turned out positively for her. It might have helped that my sorority was not on her campus so she viewed the chapters differently.
Don't be too hard on youself because the rush experience is hard on the chapter also. They have a limited time to meet the prospective members and decide who seems like a fit for their chapter. The sororities have likely picked some great girls but they have also picked a few that will not make good sisters. They have also missed some great girls - YOU!

The process is not perfect. Don't beat yourself up . Look for another group on campus to join that is more accepting.
Good luck!