Doctor discussed mental health with mother without your consent?

As a minor, issues of mental health can be discussed with your parents in most states. Only a few actually have laws protecting your privacy. I would suggest bringing it up with your the doctor in question and telling them you would appreciate not having such things discussed with your parents. The only exceptions that the doctor is required to inform your parents are when it involves your immediate safety or that of another individual.

Look up your local laws to see if you have rights as a minor, but beyond that, you sadly have few options. You can try to find a doctor that will honor your privacy if your local laws don't protect it, but otherwise you will have to deal with the fact that your medical records are generally open to your parents until your 18th birthday.