ugh, what an obnoxious statement: "I cannot afford end up spending even more from my tight budget to satisfy my DH?s self-esteem."
I know a man who has a high-paid job, and his wife was a newly qualified accountant. Because of his salary they had no entitlement to help with childcare costs, so she was basically working for nothing.
But it was what she wanted to do, to progress in her life, so that's what they did.
PS.
The basic tax credit entitlement for 1 child over 12 months working 30+ hours per week is £7305. However childcare costs can add a MAXIMUM of £7280/year to this. This totals £14,585. This is withdrawn at 39% over £6420, such that at £43,800, there would be nothing left.
So I think the OP is most likely correct that her husband would pay for everything - tax, would £1700 on £12,000, leaving £10,300 net, of which I imagine child care would cost £9-£10k, and commuting would more than take up the rest. So it would end up be working for a negative return.
I think he should perhaps find a job with some career progression at least.