I believe it takes a great deal of courage to express these types of feeling to your therapist, and I appreciate consideration of the therapist’s boundaries. If she said it was okay to text, then I would text a brief message saying that you had difficulty with the last session and it is still bothering you. Let her know that you would be willing to write it all out, but that it would be lengthy, and that a phone call might be difficult. Be sure to let her know that you are feeling bad enough that you have considered discontinuing therapy. As an EMDR therapist, I am certain she will understand.
By asking her to help you in the communication process you have already done something that has therapeutic value — while not expressing so much that it may feel like a boundary issue.
Should I Text My Therapist Out of Session? – EMDR