The first thing that comes to mind is the saying, "Hell hath no fury like a woman scorned." I think it's a good capture of the hurt of betrayal, without being too over the top.
Thanks so much for the positive feedback! I'm so happy that you enjoyed this, and thought I did well writing her feelings of betrayal and emotions. Also, I'm sorry it took so long to respond, but I really do appreciate you taking the time to review after reading; Thanks again!