I'd write it and send it. But I would also put at the bottom of the email that you expect no further contact from this point on. This statement tells her in no uncertain terms that she is not to email or phone you to give you a possible rude response. In fact, if she does contact you after you've indicated not to, she is stepping over a very firm boundary.

Also, although we all say go f2f to communicate your feelings, I personally wouldn't in this case. I've read your other posts and I don't think you need to pay this T one more cent of your hard earned money! A email is free and then you're done.

I'm sorry you had to deal with such an unpleasant and clearly unprofessional therapist! I hope you're able to find a new therapist who is able to treat you with the compassion and empathy you deserve. Good luck!