Steve, Just caught up on your thread. Sorry you are going through this.
I know your sitch [censored] and it is hard for you to not get emotional about this but reading through your thread, I feel you are trying too hard and that is very unattractive (sorry for the 2x4). You have already confronted her, so IMHO it may help to take a step back and not talk to her about this for a couple of days. Tell her she broke your trust and you need time to process what happened before further conversation. Don't have any R talks for a few days and do things by yourself. You need to show you are alpha and disrespecting your boundaries is not something trivial. Let the tension between you subside first before you talk about the sitch with her. I feel that talking when things are tense will only be counterproductive.