One has to learn to accept the "bad" as well as the good things about one's self. I'm sorry you had this painful experience, silently, but it did at least happen in your "safe" place? You had already told what she "threw back" at you, you're working on that, know it's an issue, so she can't really hurt you with that piece of information; you're working as hard as you can!

I had a vice president humiliate me in "public" in front of others and it turned out to be one of the best things that happened to me. I was able to see what I was doing, what I didn't like about what he did (and him) and make a very specific plan in relation to his behavior and how I related to him, etc.

Think about this experience and don't indescriminately withdraw; I would use your anger to discuss the situation next week and "ask" the leaders why they didn't curb such wholesale destruction and pain and humiliation and I'd let the woman know you did not appreciate her thoughtless tirade and also let the leaders and woman know if she did it again you were getting up and leaving the group forever. Let them know, in a very focus, calm manner that you were "abuseed" by the behavior of that one woman and you cannot allow yourself to be so abused again in the future!