Hi, Dfrancks. Your Dad is right. You are not in pain because of anything structural. It's from something emotionally bugging you. Maybe it is what is common to most teenagers today... anxiety about the future. But believe me, I'm 85 and have anxieties about my future. I just have to remind myself that I need to "go with the flow." Today at Mass we were reminded of the Bible saying "Keep a sense of humor, even in the most difficult times." They had them then, centuries ago, so we can learn from people back then, that we can laugh our troubles and pain away.
Keep telling yourself that the future is going to be wonderful for you. I'm confident it is going to be. Be sure to do something today that makes you happy.
Laugh, if you can. At least smile. Smiling often leads to as good a feeling as laughing.