You have a guaranteed income coming in each month, from both of you, so I think you can get through this. From experience, it's much more hellraising when one of you is self-employed or unemployed. You also have your parents property, and no doubt some equity in the mortgaged property.
Please don't panic, you are honestly not in dire straits.
Can you use a baby sitter, for part of the week, instead of nursery? This is usually cheaper.
Is there anything you can do to your mortgaged property at weekends, just to make it look a bit loved, with minimal expenditure. Perhaps weed the garden? Clear out any junk?
In the past we have had to borrow from my parents. It sucks, being a grown up, and not able to stand up on own two feet, and having to swallow pride. Can you borrow from DH's parents? It's better than payday loans.
It might sound ridiculous, but what can you sell on ebay for some quick cash?
Can you do private tuition in evenings?
Check out the credit crunch forum on mumsnet, I prefer it to moneysavingexpert. It has some great advice for cutting spending, to the bare minimum.