HI Justin, welcome to the board
. You're right, it is uncommon for a teenage boy to have osteopenia, but keep in mind its osteopenia, not osteoporosis that you have. You mention Children's Hospital of Boston, are you being treated for any other medical conditions that could be affecting your bones? There are secondary causes of bone loss that i imagine your Dr. has already looked into. Which of the once a week drugs are you taking?
Osteopenia is a wake up call that tells you its time to make some changes that can improve your bone density. Has your dr. talked to you about being more active or made recommendations? Living at home i imagine your Mom makes sure that you eat a healthy diet with plenty of fresh foods, dairy and lean protein. Has your dr. ever sat you down and told you exactly what's going on?
Sorry for so many questions
, but without questions there can't be answers. And to answer your last question, having osteopenia won't shorten you life. Unlike most of us you already know that there is some thinning of your bones and have the rest of your life to make sure they don't get any thinner. I also think you should discuss this with your parents and doctors, they are the ones nearest you and the ones to best help you deal with your feelings.
There are a lot of very helpful people here who will be glad to help ya out. take care...phyllis