how should I respond?

my best friend slept with a guy I've been crushing on for months now. and I just sent her a text and confronted her about it and she tried to hit me with "I can't believe you're going to let a guy come between us. women need to stick together and not fall out over men." honestly that's soooo shitty to me. she's using female empowerment as a way to make me feel bad for calling her out. I need a response fast!!
&yes she knows i like him but he didn't know bc i was too scared to tell him smh :(