Life with a High School Freshman

I'm a Stepmom. I have a 14 (going on 25) year old Stepson who is starting high school in just a few short weeks.
He's been in my life since he was just 3 years old and I consider him to be "mine" just as a biological child. We've shared all the growing-up stages...from Pull-Ups and reading stories before bed, watching Bob the Builder and Blue's Clues to helping with homework, begging for his room to be cleaned, and denying requests for a cell phone at 8, Facebook access at 9, and very recently, a driver's permit at upcoming 15. 
I watched him grow from that little boy who was desperate to have his "real" Mom in his life to a young man who now realizes that her absence has nothing to do with him.
I'm very proud of this little boy (who would be so mad at me for that label). Somehow he grew up while I wasn't looking.  He doesn't need me to put band-aids on ouches, hold his hand to cross the street, or call his friend's Mom to make a play date anymore. 
I'm excited and eager for him to continue to find himself over the next four short years and I'm confident he will emerge a generous, kind, strong, family-oriented, ambitious, young man, ready to be launched into the adult world. However, I'm still nervous and anxious for everything he will undoubtedly face in high school...the bullies, the broken hearts, the hard decisions that will be in this path. It's truly a Catch-22. I'd almost rather he stay that little boy, holding my hand, looking up to me for the answer. But, I know that it's time for him to start finding those answers for himself.  And, besides, what kind of parent would I be if I discouraged him from taking those big steps that lead to self-reliance, independence, and confidence? I've realized it's time to let go of the reins (a little bit at a time)...and let him grow into the young man he's ready to become.