I think that perhaps she said that this is the last straw because she was caught and didn't know what to do so she went on the offensive.
I would venture to suggest to keep up going dark because like you said, look at how often she has been pursuing you?
She keeps calling you, asking you to come over, asking you to lie down with her, etc. That is not someone who wants to be rid of you.
Yes go dark, don't contact her because if you reach out now it's like saying that you have no respect for yourself and that you would be OK with her sleeping with another guy if that's what she is doing.
Instead don't call, text or email her and wait, I bet she will call to test without asking, to test if YOU are angry or still interested in HER.
Act distinterested and I bet she will panic that she has lost you.
Wait...how did you find condoms in her bag? Were you in the house alone and she left her pocketbook there? And if they were there then she obviously didn't bring them to where she was.
