Possible Borderline Personality Disorder

I think I may be suffering from Borderline Personality Disorder (BPD). I've been researching online and have found that many of the I have many of the qualities necessary to have the disorder. It seems as if my emotions are in control of my life. I can shift moods on the dime, going from severly depressed, almost suicidal, to being perfectly content with life. How I feel about myself also changes. One moment I can be the most egotistical person, completly sure of myself and my abilities and how I know I'm better than everyone else; the next I will be totally insecure and paranoid. Suddenly everyone is talking about my behind my back, or at least in my mind they are. The only problem is my age. I am 16, and I've read that BPD should only be diagnosed in adults. I feel so certain about this, yet i don't know how to approach my doctor about it.