Ok i need a straight answer from someone who knows?

i plan on going in to the marines to become a pilot, so i planned on goin to nrotc then going in to fly. now im a smart kid, that did not use his potential during highschool and slacked a little, i did not take the SAT test because i was lacking the required math to take it and now i have graduated from highschool and dont know i can apply for nrotc and be accepted by fall or even be accepted at all, i am freaking out because i feel like my dream is being crushed slowly, what do you need to do, or need, to go into rotc, did i need a good gpa in h.s. and take the SAT... please please someone let me know so i know if i will have to wait and go to ocs instead. thankyou