Ashlee, I don't know what the current physical fitness program consists of at Navy boot camp. But when I was last a Navy DI (RCC), in the early 90s at Orlando, our CO completely changed the running portion of the PT. New recruits were required to run, not walk, for a period of time. I'm thinking it was 9 or 10 minutes. No one ran in formation. It was run at your own pace, but run, or jog.
After a couple of weeks of training, that time moved up to 12 minutes.
And so on, until most recruits were running for 18-20 minutes. Then, when the final test came, almost all could pass the 1.5 mile run, since it only took about 16 minutes.
Once in the Fleet, the 1.5 mile is a run/walk event. I used to run 3 minutes, walk a minute, run 2 minutes, walk a minute, run 1 minute and look to see how far from the finish line I was.
Good luck. Start running now. Just a jog. Don't run for distance, just for a length of time. Start slow, work your way up.