It's a double edged sword unfortunately. You did something wrong, you know that, and you confided in a therapist for help. You would think you would have a "safe zone" to spill your guts in order to get the help you need, but the therapist is in a position where she doesn't know that this was a one time mistake, and she has a duty to protect those who can't protect themselves.
I would make sure you drive the point home that this was a one time mistake and it will never happen again.