The guy who said don't sweat the small stuff is right. It becomes so easy to get into arguments over nothing when you are with someone so often.
Here is another thing, that I think is critically important and not discussed openly enough because, well, it's a difficult topic:
The other advice I have for you is to take care of your yourself physically and try to encourage her to do the same, in a respectful way. Keep up physical appearances and make a long term effort at intimacy. Why? You are both -- but particularly you, as the male -- are trying to do something extremely un-natural and against human nature, which is commit to one vagina for the rest of your life. For reasons that are likely obvious to anyone with testicles, by default you are at serious risk of getting bored and being tempted by other women, especially as you both grow older and become infertile. Evolution has programmed your brain to plant the seed in as many uteri as possible. In order to avoid cheating, you need to do everything possible to maintain romantic intrigue/interest in your marriage and part of this is making sure you are still attractive to each other. You are in the first inning, from what it sounds like, so this may sound like the furthest thing from your mind today. But trust me, over time you WILL be sexually attracted and want to fornicate with other women, even if you defy the odds and remain totally satisfied in your marriage.
Tis a tale widespread and old as marriage itself: man and woman fall in love, man (and/or woman) cheats, marriage falls apart due to loss of trust. Just be aware and be prepared.