I hear you op!
I have 2 dcs. One at comprehensive and one toddler. I work from hime about 4 hours a week.
There is always something to do. Always.
Yesterday I did all the downstairs. Today I have vacuumed and cleaned up stairs. I have beds to make back up when the bedding is washed and dried, downstairs looks like a fisher price bimb has gone off. I need to vacuum downstairs, clean the downstairs loo, book a windscreen repair, sort some more clothes out for putting away, wait in for the electrian, buy some milk, do lunch for me and ds, look for something in the freezer for tea, take dcs to a family birthday party later plus deal with a demanding toddler for the day.
Tomorrow I have to sort out the freezer and kitchen cupboards ready for Christmas food, will need to tidy downstairs again at least twice, sort ds's toys out ready for his birthday styff coming at the weekend, finish wrapping his presents, rustle up some proper food for tea after freezer surprise tonight, try and get the rest of the outside Christmas liggts out of the shed etc etc etc.
It's fucking tedious. And my standards aren't tgat high. I do enough to keep us in clean clothes, able to have friends drop in unexpectedly without feeling shame and decent cooked food at least 5 nights a week. Friday is takeaway night. Sunday it's graze in what you can find day as we tend to have lunch out somewhere.
I long for a childfree day just to get shit done. Dp works long hours in a physically demanding job so although he pitches in when he is around (when prompted) he is usually exhausted after work and is in bed from 9pm.