OP,

1.) You are TA. Your husband has done nothing wrong.

A.) He merely stated that he couldn’t take Billy to your parents because he had work; professional obligations. It was a statement of fact, not an attack or slight at your parents.

B.) Regarding his comments in the natural remedies, he merely stated his professional AND qualified opinion. As a medical practitioner, especially of pediatrics, a field that deals with minors who can’t assert their own autonomy (including to give consent) easily, he likely felt duty bound to speak up. Depending on the remedies and/or condition not being treated, he may even be mandated to report it.

Point being, your husband has merely been carrying his professional obligations and you’re wanting to isolate him for it. If you didn’t want to deal with the baggage of a person being a doctor you shouldn’t have married a doctor.

Unless you plan on ending the marriage, you should tell your family you’re not leaving him alone.