It sounds like she didn't really invade your privacy (just that she's as clever at putting two and two together as you are), and that the bottom line is you don't want her to be part of your life. Remember, the jealousy is about what she represents, not about who she is as a human being. Recognize your feelings
as being just that.
Frankly, it sounds like you're just really, really angry: at him for being tactless in his enamorment, at yourself for getting sucked into it, and at the other person for having this impact on you. Be careful though, to not mentally convict this other person of some crime she has not committed and behave as if she has. There is a line between feeling jealousy and acting petty.
It's totally okay to take time to yourself if you can't talk to him. It's okay to not want to talk to her. It sucks that this is hurting you, and honestly, I feel for you
. Some sleep will help you clear your head. Be strong. No one can look out for you better than you can.