Hello and Welcome to JustAnswer. Your question is not closed until you are satisfied. I am happy to assist you with your question.
I think your best bet would be to find someone who does cognitive-behavioral therapy with a specialization in phobias. This person should be familiar with systematic desensitization therapy. You might also seek out a dentist who works with general anesthesia, so you can sleep through the procedure. By the way, I agree the psychiatrist was not appropriate and you did well to stop seeing him.
Please let me know if you have further questions or require clarification about anything I have said.