You seem to be taking this very well - but as you say you are numb and probably in shock. It's awful to be betrayed like this by people who are supposed to care about you. I probably wouldn't wait to confront them if I were you - the sooner the better, in fact I would take that email and make one of them read it to me.

I hope you are able to move past this and get on with your life whatever you decide to do - no one deserves something like this to happen to them.