I think when starting out with something like this it's easy to feel overwhelmed, I reckon a meal plan would help. You think this is going to be harder then the status quo but if you move your diet more in line with what your children are eating that becomes the focus of meal times and you can supplement your husband's meal with the addition of meat.
Assuming he's a meat and two veg kinda guy start with meals from that category you can tweak for the family but share the same potatos and veg around you all. So each week pick two from:
Roast dinner - you all have nut roast/stuffing/veggie sausages/whatever, he gets a couple of slices of meat or a piece of chicken on his.
Mushroom wellington - he can have an individual steak pie instead
Spiced butterbean and veg pie - he gets an individual chicken and mushroom pie instead
Bangers and mash - veggie/vegan sausages for you, meat ones for him
Cottage pie- quorn/lentils/veg for you
Then do one pasta dish a week - roast veg pasta, pasta arriabata, lasagna (as per cottage pie), spag bol (as per lasagna), meatballs (use the sausages), smoked salmon pasta, spicy prawn pasta, etc
Then a curry once a week - Indian - daal, brinjal bhaji, vegetable jalfrazi, saag aloo, etc. Thai prawn curries (pick your variant). Again stick some tikka chicken or something on the side for him.
One fish dish a week. Fish and chips, spicy fish cakes and tempura vegetables with dipping sauce, Salmon en cruet, etc.
What are we up to? 5 days covered?
One rice dish a week - seafood paella, mushroom risotto, lemon risotto, vegetable biriyani, veggie/prawn special fried rice, etc. Again add meat to his if you like.
Then one anything goes day. Jacket potato and topping, warm root veg salad, burgers (veggie or meat), individual pizzas, etc.
Once you get into a routine you can try new recipes