Attila's post makes a lot of sense.
Do you know, when I started to read this post, I expected to read that you (plural you - you & DH) were in debt, struggling to pay the bills or whatever, and that that was why you needed to go back to work.
Unless I've missed it, I haven't read anything like that and it comes across as bullying pure and simple. It's not the right attitude to take, but he comes across as being jealous of you being at home so he belittles you out of spite.
You have one pre-schooler FFS ! I have too .... and am incapable of earning, in a "normal" 9 to 5 job "enough" money to cover off childcare, travel and enough take home after that. So instead, I work very long hours - certainly equivalent to a full week's work, if not more, at home, for an insulting wage, in the evenings and weekend. Which makes me a pittance, but still more than take home from a 9-5 job.
Belive me, if I didn't have to do this, I wouldn't, because I have no "me" time and neither is there any "us" time. It's a nightmare.
BUT ...... DP did not force me into this. Nor has he gone on and on about me working 9-5. Truth is, if I did have the skills to work 9-5 and bring home "enough" then that is what I'd do, but unfortunately the high cost of childcare (even if using a Childminder - no offence intended to any CMs) means I am in a Catch 22 situation.
You sound as if you're in a similar position with a 3 year old who will need full time care and 2 others who'll need wrap-ropund school care, plus holiday care. What would you actually end up with once childcare had been paid for ? It very much sounds as if you'd end up with nothing and therefore, what would be the pointy of you working, and the kids having to be looked after by someone else ?
If so ..... why on earth is he pushing you on this ? ..... it'd be no good for you and no good for his children either if you are working for nothing.
Is there genuine financial need here ? ..... and please don't say there is because you have "your" credit cards to pay for. "The" credit cards (not "your") have been used for food FFS - and probably kids' clothes, am I wrong ? That is household and not your sole responsibility.
I know you may not want to go into details about his income but does he give you £200 per month because that's all that's left over after the mortgage etc., or is it because that's simply what he does ? £200 + Child benefit sounds a very tight amount for a household of five if you're expected to fund all food, toiletries, clothes, kids' incidentals from it.
You know I might be barking up the wrong tree but it sounds like petty spite and control going on here rather than genuine stress and worry about making ends meet. Even if you are all genuinely brassick, the fact remains that unless you are a reasonably high earner, ideally with low commuting costs, the childcare costs of 3 children would mean that most working women would just about break even. So I keep coming back to what I've been saying about the "point" of all this.
Have you actually presented him with the figures ? ....
.... he firstly, job or not, needs to be shown just how much Tescos costs each month + clothes + shoes + any activities + petrol, and that you running up credit card debts is a ridiculous state of affairs as the capital debt is never reducing and without any income, you can never be expected to pay it off.
Secondly, he needs to be shown the sort of take home pay you can get from jobs you can actually get less childcare and less commuting costs. If the end result is nothing, what is the point of you working at this moment in time ..... unless it gives him a "kick" you've done what you're told and he no longer feels "it's not fair" that you "apparently" don't work by being at home.
If your household does have genuine money problems, then you need to tackle these together by looking at all the money coming in, checking where you can ecconomise, looking (maybe) into evening work for you where childcare isn't required and so on. But the "domestic" bills are not your sole responsibility .... he may be bringing home the dosh but you are making an equal (probably more than equal dare I say, because you don't stop at weekends) contribution in other, non-paid ways.
I am furious for you because reading between the lines, I've not got any impression of money problems .... just of a spoilt, unreasonable bully who isn't even (assuming the need for more money was genuine) going about it in an adult fashion ...... belittling you and insulting you, cutting you out of family life.
To be brutally honest, if you did split from him, you probably would be better off financially as you'd then qualify (by the sounds of it) for full Working Tax Credits and that'd mean a very large part of your childcare would be taken care of. Even if you don't do anything now (I can't tell you to do that) there is no harm at all in you finding out how you'd stand on your own. Maybe start with the CAB, or speak to the benefits helpline. I know the IR have a tax credits calculator on their website which will also help you get things into perspective.
He sounds awful and I'm sorry you and your children are having to go through this.