Welcome "biggie" to the forum.

There's no way to know "how big you will eventually be" and by searching around in the various threads (particularly in the Young and Hung section I believe) you'll find numerous posts with other guys all sharing your concerns and, at this point-- your speculation as to what's to come.

For the record, at your current size--indeed, you are big enough right now to do the job! ;)

My advice (perhaps to be joined by other posters here) would be you still could grow some more. Many guys don 't stop growing until they near their late teens or early twenties.

So, enjoy "life's ride to maturity"...accepting what size you wind up with and knowing all the while it's not the size of your gear that ultimately makes you a man!