Nukes_wife, I was right where you are about a year ago, so feel free to PM me if you need any advice and/or support. We got married (at 26) right after Power School, so I was here living with him while he was on hold and during Prototype. I just want to second what other people have said as far as your husband's effort being the most important factor. My husband also had a hard time passing math, and, actually, struggled with more than he probably wants me telling to random people on the internet. But, he got through it, and so will your husband.
For better or for worse, right now you're married to his Navy career. I agree with what other people said about the best thing you can do is to keep things stress free at home. I can't really advise you on how to do this while also dealing with a baby, as we made every effort not to at that particular juncture, but I know quite a few people that have. I just made sure, no matter what shift he was on, that he had dinner ready for him and that he got an hour or two of worry-free decompress time before he had to sleep.
And playswithairplanes was not in any way insulting you, he was giving you his honest insight. The wives that seem to have the hardest time are the ones who see themselves as some sort of saint, martyring themselves for the cause and expecting to be acknowledged for it, which is what I took his response to mean. Chill out. You will run into a lot of people on these boards with a not overly optimistic view of marriage in the Navy (or so it has seemed to me, as a frequent reader and infrequent commenter).
ETA: Just think of little things you can do that will be a load off his mind, even if just a small one. While my husband was in Prototype, when he was relaxing before bed, I'd get his lunch for the next day together and in the fridge, so he could just grab it and go in the morning. When I was feeling super cheesy, I'd put little napkin notes of encouragement in there. Seriously, anything you can think of that will allow him to have less on his mind while he's at home and able to relax, the better.