Re: Chest pain that wont go away! please help!
He might be assuming it's muscular-skeletal because you're so young and exercise heavily, but I hope he also checked out your heart and lungs. If it IS muscular-skeletal inflammation, you should cut back on exercises that could aggravate it, such as rowing, chest press, heavy lifting, etc.
If you didn't get an EKG and a cardio workup, I'd ask for that now. When I was young I had a heart arrhythmia that sometimes felt like a fast heart beat, and sometimes it just felt like pain. It was like a short electrical charge that caused extra heart beats. I was able to pinpoint things that made it worse - alcohol, caffeine, a particular sinus medication, and of course stress (especially when I was late or feeling rushed).
Note - it's hard to pinpoint a problem based on the LOCATION of pain, because our network of nerves can make us feel it somewhere else. It's called referred pain.