I honestly don't think I'd be able to tough out the rest of the degree when I know I could be enlisted now and (hopefully) making a difference.
It's good you're being honest with yourself. But one more thing you should ask yourself is why you don't think you'll be able to finish a degree right now. If the reason has to deal with being young and not having the maturity/responsibility/discipline to get good grades and finish, that's perfectly fine. Plenty of young people, myself included, struggled with that; enlisting in the navy will definitely provide you with discipline and responsibility and you'll have time to mature before returning to college if/when you choose to. Like I said, I'm in damage control now because of those types maturity/lack-of-focus issues, and I'm trying to improve my gpa by retaking classes and trying to pursue a master's degree in order to become competitive for NUPOC. Looking in retrospect, I wish I would have entered the military out of high school, or at least when it was apparent I was not focused on school.
But if the reason you think you won't be able to finish a degree is because it's hard for you to grasp the material, then may I suggest thinking about another field within the navy. All nukes, enlisted and officers, attend power school and prototype and from what I've heard neither of those schools are a walk in the park. I'm not saying other jobs in the navy are easier, but if you're struggling with technical material now, then more technical school might not be in your best interest (power school will teach you heat transfer, thermodynamics, physics, etc.)
You seem to have your head on straight. Stay honest with yourself, work hard, and best of luck to you.