I'm don't understand. Is he REALLY expecting for you to go back to work, pay all the mortgage AND all the nursery fees? This sounds like it was an unequal relationship from the start. I really wish women would think about what they're doing when they choose to have children with men who don't want to be in a proper partnership with them. And vice versa.
You have a situation where you have a man living in your house which you pay for and own (and he doesn't have any part of), you and he share the other bills yet he doesn't want to contribute towards nursery fees. So he's basically a lodger and sperm donor who does a bit of childcare now and again, like a friendly uncle. Maybe that's what he feels like too. It just doesn't sound like this is a real grown up relationship all round really.
Is there a reason why the house is not jointly owned and paid for jointly? Is there a reason why you are not married? They're both red flags to me, when there is a child in the picture.
Just to compare to my experience. DH and I bought our first property together after we got engaged and were married soon after. He earned a lot more than me and so paid ALL the mortgage, but we BOTH were named as owners of the house. We shared the bills. When we had children, we had just moved to a different area and I was between jobs so we decided TOGETHER that I would stay home for a couple of years and not only would he continue paying all the mortgage but all the bills too. He recognised that I was providing childcare for the children that otherwise we'd have to pay for, and I recognised that he was paying for our housing and bills costs to enable me to stay with the children.
When I went back to work PT (didn't earn a lot), we did discuss childcare and basically saw all our money as part of a family pot. He STILL continued to pay ALL the mortgage and ALL the bills, I paid for childcare (not much, top up after the free 15 hours), and all our "extras", like holidays and days out etc.
As a consequence, when I came into a large inheritance a few years back, I had no qualms about paying the rest of the mortgage off, buying him a car, paying for nice family holidays etc, and he STILL pays nearly all our bills. I pay towards the kids' uni expenses and will also think nothing of supporting us both if he wants to retire a few years early.
I'm just illustrating that there are many ways to organise family finances, but the most important thing is that you agree these things together and you work as a team, have each other's back, providing for each other as circumstances change. You aren't working like that at the moment. Figure out if you both want to, and how you're going to do it fairly. Personally if you really love and value with each other I'd start with figuring out why you aren't married and why you don't own the house JOINTLY as equal partners.