Is my employer allowed to divulge my personal information with a co-worker, without consulting me about it?

My manager gave every personal detail about an aspect of my personal life to a co-worker I have yet to meet. She even called me and asked me to give the girl advice after. It was a very personal issue that I do not tell people myself. It was completely unrelated to the workplace. Just something the manager knows from necessary paperwork for employment and her asking about it in the past. I live in North Carolina. Is there a law protecting my violating of privacy, and what can I do? This is just one issue I have with this employer.