Oh yes, I know your situation only too well when it comes to expectations of free childcare and the result of saying NO.
I believe that if you can't afford to have children, then you shouldn't, but rather wait until you can, or until you have reached that time when the old biological clock is ticking and time running out.
My youngest son and his partner decided to have a baby, even though they knew she would have to go back to work almost straightaway to help keep them afloat financially.
'Of course', my son said, 'we know you will help out'. I asked what he meant. 'Looking after the baby for us'.
I was truly gobsmacked. I have health issues, and have had for quite a while now, had them when this baby was expected. Some problems with balance being amongst the issues. I had given up driving, hadn't a car, to get to them by bus would have meant two separate bus trips. I had my own life, a part time job which I loved, and now with no dependants at home, a little spare cash and freedom. I was in no way a suitable person to look after a baby/toddler, which is what they were expecting of me, even though they knew about the health problems,that some days I just felt too rotten to do anything.
So, knowing he could be a bit touchy and impatient at times, likely to run off at the mouth without thinking, I wrote to him, saying I wouldn't be looking after the baby, physically wouldn't feel safe or comfortable doing so, and that they would have to make other arrangements.
I got a very rude, hurtful letter back. That was over ten years ago, and despite my best efforts to heal the breach, he has made it perfectly clear I am an unfit mother/grandmother, don't deserve a family - blah blah blah. He hasn't spoken to me in all that time. We did see our granddaughter a couple of times, but not since she was 18 months old. Yes it is sad that this child, and her younger sister, are being deprived of two loving grandparents, don't even know of our existence. But I am not going to carry on beating myself up about this. It is their loss. I have moved on. Bur Christmas can be hard, as you might imagine.
I hope you get your situation sorted before it escalates like mine did, though I have to say, and sorry if this offends, but it doesn't sound like he had much respect for you in the first place, and frankly, I think you were a saint to put up with his shenanigans as long as you have done. Be strong.