What was her end game with the initial texts if she was going to be so rejecting and firm when I responded? I'm confused and sad and feel pathetic for feeling that way.
I will speculate here and say she is trying to take control back given you ended the relationship. No one likes to be rejected and for a borderline it is particularly hard. You are not responsible for her feelings but you are responsible for yours. I think you have realized that NC is probably the best thing for you right now. Would you agree?