If you are not going to be 17 until December '24 during your freshman fall term you are very young for your graduation year.
You are getting lots of realistic feedback here. The reason it's hard to make the 800 team is the same reason it's hard to make the swim team - D1 sports are extremely competitive. A&M is famous for being 800u, with a bunch of national champs.
This all said, if that's where you're going to school, why not give it a shot this spring and then fall and winter in college and see how you do. Set small goals, 2:05, 2:02, 2;00, 1;58 and enjoy beating those targets along the way. Run a few 400s and miles for variety and a check on speed and endurance.
A&M is huge, so there must be a great running club.
Someone also mentioned triathlon. If you can combine a decent 1500m outdoor freestyle with your 5 min (and improving) mile ability, you could actually be good in tri. A&m probably has a good tri club too.
Good luck.