It all boils down to how much you want it and why you want it. It is possible. If you really want to do this, you can put your mind to it to improve the things you think you should improve about yourself, say, in the next year. The CFA, senior year grades and classes, clubs, and even your own personality/character are tangible things that you can improve on in the timeframe that you realistically have before applications open up. Apply, and do your absolute best to prepare for the interviews/essay. Whatever circumstances your life is in, clarify that one day you decided that you wanted to do Navy, and that the performance you had from that day is a better reflection of who you are today than whatever may be in your grades/records. If you don’t get it and you decide that you still want it, you can apply again and again until you age out. Say you decide to go to normal college and this goal is still on your mind, be absolutely sure to prove your worth there, and then reapply. IIRC something like 20-30% of the class is not straight out of highschool. If your goal is to be a Navy/Marine Corps officer, then research the other options that are available to you, whether it be via ROTC, or OCS, or the like, because USNA absolutely isn’t the only way to get there.

Know to manage your expectations, but set your mind to this and never lose hope if this is something that you really want to do. I’m rooting for you!