Is he napping at daycare?
He needs to nap.
Next, you need to plan your menus & grocery lists every week, so you know what to cook & buy, and its not just at the moment cooking.
Then, cook some meals ahead of time, so you just have to heat it up.
Or, freeze it, then thaw/warm it up for dinner.
Also, he should ideally be eating dinner earlier than you both. A kid can't wait until say 7:30 to eat dinner after you are done cooking.
But at the same time, you need to know that he is eating during the day time... it is just not what you cook. So to a certain extent, you need to accept that.... or you will run yourself ragged making extra food for him.
Or, just provide ALL his meals/food for the Daycare too... and tell the Daycare provider he will eat your food, not what they provide. Then that way you will know what he eats... and it will be your food.
But... that means you have to spend EXTRA time cooking his breakfast/lunch/dinner.... as you want him to eat. And even though he gets breakfast and lunch there... you are also making an extra breakfast for him... and lunch. So there is a lot of duplication and extra time you are spending on making meals.
BUT... are you "paying" for the Daycare food? Because you are making him his food... so that may be extra cost for you, if you are also paying for the Daycare meals.
Also though, as he gets older, and then on to Preschool & grade school... a child will be eating at school. Will you continue to make him his own meals.... or "can" he eat at school... thereby you don't "have to" make him all his 3 meals a day???? Or will you still be making him 3-meals a day... even if he gets food/meals at school? Do you know what I mean?
And yes, an overtired kid, cannot eat well. Most kids are that way. Mine included. So, you have to provide him with a snack/meal... BEFORE dinner. Or make that his dinner.
On the weekends when you have time or you have to make time... cook all the entrees/meals you can... then freeze them. So that during the week you can just thaw it in the morning in the fridge before you all leave the house... then when you come home, just heat it up. Thereby cutting down on time expended to make dinner and then eating and then cleaning up after dinners... then he has to bathe and get ready for bed.
And, for errands... try to make a weekly list of errands you need to do. And try to do that NOT after work.... otherwise by the time you get home it will be way past 6:30 that you can get home. Try to do your errands on non-week nights... or just have your Husband do it, so you can be home on time cooking dinner and getting him wound-down and ready for bed. At a reasonable time.
The thing is, he is getting lack of sleep... if his bedtime is late due to dinner and prep and errands. Then the next day if he is not napping... it just compounds the problem of his lack of sleep. Then by the time you all get home in the evening... he is just TOO tired by then... then he can't eat well because he is too tired.
So, adjust your timing for things and prep/make dinners ahead of time... and freeze them.
Or, get a crock-pot, and you can "make" dinner in the morning, the dinner will be cooking in the crock-pot all day, and when you come home it will all be done. Ready to eat.
all the best,
Susan