First off, congratulations!
He loves you as you are enough that he wants to spend the rest of his life with you. I would advocate starting to eat primally for the health aspect of it, but you're going to have enough stress on your plate with the wedding and all the preparations that go with it that freaking out because you aren't losing a ton of weight on a primal diet probably won't be worth it.
I say enjoy the experience, eat primally as much as you can, but don't get wound up over it when you can't. Getting married is a wonderful thing, but it's supposed to be about the joy of committing yourself, body and soul, to the person you love...not looking shit-hot in the photos.