Real friend?

So I had a really bad scenario with my step brother, he sexually harassed me, if you wanna know the whole story look at my profile. But my friends know about it and I have bad nights and good nights, and my one friend asked me for help with boys one night and I was already crying so I told her I’d love to help but right now I gotta focus on myself. And she was completely okay with it until about an hour later she unadds me on Snapchat, and is telling people that I’m such a bad friend, and we’ve been friends since we were 4 and now we’re 14. Did I do something wrong? Any advice??