My rights if I feel the confidentiality of my personal health information compromised?

I currently work in good standing with a health insurance company. My record at work has been exceptional in my 10 years there. The reason I'm writing is to find out my rights regarding a situation that happened there. Over 3 years ago I checked myself into an alcoholic rehab voluntarily to take care of a problem I had. I used appropriate means to do so and took approved time off for those 10 days. I confided in my boss at the time and had her full support. This problem never affected my work performance. Now, some 3 years later I have a new boss. I had to leave work just before an important meeting because I was sick, this put my new boss in a bind, but there wasn't much I could do about that. My new boss followed up with me in a meeting and told me he knew about my past problem with alcohol and wondered if this was going on again. He should never have known about my past problem. He wasn't even here when that happened. I feel like the confidentially of my personal health information was compromised. Could you please tell me what my rights are? Thank you