If I'm over 21 and I just found out the therapist my mother suggested I see is telling her everything I say, what recourse do I have?

You have the right to speak with ana ttorney about a caise of action against the therapist for a breach of confidentiality. The privilege of privacy is the patient's, and ordinarily a therapist needs a signed release to breach it. Any licensed therapist who breaches confidentiality without a patient's approval is open to a lawsuit and can lose his license for violating professional ethics. Seek consultation.