As for Basic Training, remember this: they pay YOU to eat right and exercise. Everything else revolves around that. Normally, you pay to eat right and, if you do this outside the home, to exercise (spa/gym). Sure there's yelling, hollering, in-your-face-are-you-eyeballin-me?! moments (which resolve themselves in more exercise), but I'm sure you got that treatment before. Lord knows I did, though the exercise wasn't pushups, but weeding the gardens when I chose to go against the Rule of Dad.
The Drills' job is to train you, get you fit, and to try to break you. They want to know your snapping point. If they break you, they can remold. The game is not to break. They need to know how much pressure you can take, be it in a warzone, natural disaster, military office, or handling gifts for Toys for Tots.
For the most part, yes, you will not have control. But you still have choice. You can choose to do what the Drills say, or not. Both have consequences, albiet the former is bound to be more pleasant than the latter.
Be at peace, and know this military brat will be pulling for ya.