You’re being too hard on yourself. Breaking up a friendship because someone does something super terrible to you does not make you a bitch or unkind or unethical! Take some of your lifelong training to be kind and turn it inward. Maybe at some point you’ll feel that you can forgive her (and maybe not), but it’s really OK to not be ready to do that now. If this is tearing you up inside and making you miserable, please consider talking to someone more 3 dimensional than me, at Counseling Services bit.ly/BC-counseling.