Yea Trc I was going to mention that too, you really sound like a solid kid. Are you riding that 14R on the street and keeping out of trouble? If so that's very commendable.
I'm 35 now, here's what I did. I live in Colorado and toured my balls off from age 20-30. I also rode my mountain bike all the time and played a shit load of awesome video games. I had no idea what I wanted to do with my life and was severly depressed for most of those 10 years. I was working a shit job in a restaurant the entire time with very few friends and no girlfriends. Riding was my life and I've got 100,000 miles worth of purely recreational miles to prove it. Crash free btw.
I rode to California 7 times and even wrote a book about my experiences and how it added such glory to my life. I got laid off from that restaurant job in '08 and was lucky enough to get an entry level job in the surgery dept of a hospital during the recession no less. I fell in love with a girl there that I could have married, we moved into together then she broke up with my 2 months later because I don't want kids, but I still wouldn't trade that experience for nothing and she wasn't for me anyway.
So now, purely because of this job and that girl, I'm nearly done with a medical technologist degree and feel very good about my life, something I felt was impossible in '03 the first time I rode to Califoria.
The bottom line is this: If you don't know what you want to do by now you probably won't for many many years. Enjoy your youth. Racing could be your calling and excellent motivation to lose that weight. Your metabolism, muscle mass your physical health in your teenage years, set the tone for the rest of your life.
Everything works out in the end.
And go see a urologist!