Hang in there at college - do the AFROTC thing and keep your grades and physical condition up.
If you don't wear glasses (I think vison correctable to 20-20 is acceptable for some flight assignments, not fighter pilot) go for pilot training, not everyone gets to fly a fast shiny jet fighter. Somebody has to fly fast big not so shiny bombers and transport aircraft and - yes - the helicopters (by the way - there are no longer any shiny aircraft in the military, too easy to see).
If you get through pilot training you can ask for helicopters. If you are the hottest thing to hit Air Force flight school in the last ten years you can get what you want. If you don't want to be a fighter pilot the Air Force is smart enough to know better than to put a guy in a 100 million dollar airplane that doesn't want to be there. You have got to want to be a fighter jockey. It's a busness with a lot of opportunities to die.
On that subject, Infantry, either Army or Marines is not all fun gun shooting. Sometimes there is someone shooting back. Again there are lots of opportunities to die. A hellavu lot more than being a fighter jockey or a helicopter pilot (unless it is Army).
With the subjects you are majoring in you can try for Air Force intelligence (or Army, or Navy). In other words, excell in school, keep your self physically fit, avoid like a passion the dorm/frat booze and pot parties and you can write your own ticket.
One last thing - though the military seems like a real fun adventure - it is and it isn't. You can have a lot of fun but you are sworn to die if necessary for the call of your country. Lots of young Americans are dying in Iraq and Afganistan, and wherever the next call comes in the world situations we face today. Keep that in mind as you pursue your dreams.
Oh, by the way, except for navy pilots (landing 50 tons of fast moving airplane on 500 feet of pitching aircraft deck), the Navy is about the safest service right now. If you really like water, love sleeping in bunks above or below with fifteen or twenty other guys in real close quarters, are simply mad about being away from home and loved ones 6 months or more at a time, and think a storm at sea is a real thrill - go Navy. But don't become a medical corpsman because you travel with and patrol with the marines (you can get shot - or blown up by an IED).
Be sure of your choices as you pursue your dreams.
Jimmyj68 - 20 years USAF, 19years six months DOD Civilian Service