It sounds like you can compromise now on your lesson planning when you have a choice and a partner, or you can compromise later when you're a single mom with your work and you no longer have a partner by showing exactly how much you value him in your marriage of yourself, him, and your work.

Some ideas to alleviate the tension:

• Leverage friends and family for help - a weekend here or there free of the baby or someone to handle some of the yardwork isn't long term sustainable, but if can be a stop gap for you two.
• Figure out extra streams of income, whether that's renting out a room in the house, or some other form of leveraging your existing assets. Extra money means flexibility. He doesn't need to accept being poor forever and you don't have to either. You paint both of yourselves into a corner by believing this. You have a major asset to leverage. A home.
• Meal prep the same foods every other week. I highly doubt your husband's and your food tastes are so completely mutually exclusive as to prevent working together. One of you is vegan/vegetarian? Won't kill the other to adapt for a week and keep the meal prepping optimized.
• Offer to take up some of the low-maintenance chores that you can set and forget - laundry, dishes if you have a dishwasher.
• Take one night a week in which you don't lesson plan but rather dedicate to the relationship by being a supportive partner.

Good luck. I hope you get the help you need and you're able to find a way to work things out with your partner.