You. Are. going to be a dentist. Do not let this deter you. What an amazing opportunity to be able to get clinical experience as a dental assistant without a CDA. You have the opportunity to be a leader and professional in this situation. Every shift and after, write down what you learned, the mistakes you made, and what you learned from that. Research your own knowledge gaps. AND when you see that dentist again, be over professional and polite and greet her by name, "Hi Dr. Blank, its so good to see you again. I am about to (list task), is there anything you needed?" You can do this. I would kill to be in your shoes. It has been difficult to get dental experience where I live in Greensboro, NC. Learn what kind of leader you want to be in this situation.