Workout motivation and tips??

So I'm I'm ROTC and we have to do the presidential fitness test every semester. We ran the mile last week and I got 17:35, which is absolutely unacceptable. I'm so out of shape, and I'm starting to become unhappy with the way my stomach looks. I don't feel fat necessarily, Im just not happy with my body at all. I'm weak, I'm gaining weight, and I'm unhappy with my body overall.

I don't exercise at all as of now, and I get winded just from running up the stairs. I need a workout plan that starts me off easy and gets me on track to a good workout routine. Any suggestions at all?