Wow...dh and I are youth pastors, and trust me, teenagers can have serious mental health issues too. One of our students was so textbook manic depressive, but all of our efforts to get him help arrived in the same answer, "Oh, no. He's too young to diagnose him with that."
Until he attempted suicide during one depressive period, and then tried to kill his mother during the next. Even then, he wasn't diagnosed until he was hit by a car and had to be care flighted to a bigger hospital for his head injuries. Turns out, the meds they were giving him for his ADHD were only making things worse (duh!) and he was trying to self medicate with caffeine and energy drinks. Why don't people just look at the evidence, and not decide before hand that it is impossible?
I can't believe one doctor would second guess your regular physician's diagnosis and just decide on one visit that they know more than the doctor who has been seeing you. That's ludicrous. I really dislike doctors who try to make you believe that your sympotoms are psychosomatic. Never, ever see her again. Next time, she might decide you're moody because you're hormonally imbalanced and put you on birth control.
Be a light unto the world...not a bug zapper.