I'm sorry you're so stressed out about this. I hope you get the situation resolved soon. I also think writing him a letter would be a good idea. Hopefully, your therapist had some suggestions for you.
Let us know how that went. And don't back out of the Lamictal now! It will take TIME. Please be patient with it. We all want you to be feeling better soon. It should help you feel more confident and less anxious. I know the mood stabilizers help me with that!