OK, first tell him you are not happy with your current financial set up. Not the amounts, and not his attitude.
Write down all your joint household / family outgoings. Add up all the Christmas, birthday, uniform, clothes costs, divide by 12. Don’t leave anything out. Cars, window cleaner, school trips etc etc.
Show him what you cover. Work out what % of your income you spend on all this
Work out what percentage of his income he spends on family / household.
Tell him that childcare , nursery fees plus any days you do, plus drop offs etc enable HIM to work.
If he will not agree to a better balance of payments, as described by a PP where income and costs come out of the joint account, then I would tell him that you will be getting a f/t job. That you will pay fo and arrange childcare for exactly half of each week, or 5 working days a fortnight. Tell him that he needs to arrange and pay for all the childcare on the other days. Drop offs, sick days, everything. And do it.