31 is not old, and you aren't a beginner. Being mature, you're way ahead of the "stupid things I did while in College" contest, which will allow you more time to practice and study. You aren't testosterone driven, having been there, done that, and 20 year-old flute players have nothing against us a 31 year-old. Vulgani of my age don't fare so well.
You have a dream, to be sure, as most music majors, but you also have purpose, and that will be a huge advantage. You'll get cheap tickets for football and basketball games, too!