This is hardly your fault. Revealing herself and then swearing you to secrecy is just further emotional manipulation. She treated your horribly and you still felt the need to protect her. This woman's a pro.

I am upset, but again that's not your fault. I'm usually good at spotting sociopaths or emotional abusers because there have been far too many in my life. I hope that makes my reaction a little more understandable. I'm feeling a little unsafe right now, and the best way for me to deal with it is to withdraw for a bit instead of having a big dramatic fit. I'll be fine. I just need to re-evaluate some things about myself.