This sounds like you have already done the rational thinking about moving forward, and it sounds like you realize it is worth moving forward. My suggestion is to trust the logic; emotions can be deceptive. You know that: your emotions usually have had you run away from things. You didn't do that this time. That is growth.

One of the most important skills my therapist taught me was that I have a choice in how I react to a situation. You have rationally already made the choice, and it appears to be grounded in good introspection and fairness. Let the emotions go.

Sometimes in life we just have to let certain things go. I'm not saying excuse what she did. You have already had those conversations with your therapist. She's aware of your objections. You both have taken some concrete steps to prevent something like this from happening again. That's mature, rational, problem-solving. Let the rest go so you can move on. That's what I would call forgiveness - and this is the truly comforting kind of forgiveness where the other party has taken responsibility and worked to make amends. Let the hard feelings go.

In relationships that matter and that are healthy, sometimes we have to take a deep breath and make the decision to move forward rather than hold resentment for a particular situation. Healthy relationships can "move forward" because the healthy people in those relationships can see the true effort and caring that is worth letting some things sort of just wash away. You do seem to have a good therapist and this therapy relationship is much healthier than some of the ones you've had in the past. Breathe deeply, realize you've already forgiven, and recognize that through your discussion and problem-solving together, the issue does seem to be worked out. You just have to make the choice.