While your wife needs help, you also need to look after yourself and the kids.
It's not weak to ask for help, in fact it's stupid not to. Now's the time to call in some favours and get any relations and friends (that you can stand) to come and spend a bit of time with you.
In days gone by, everyone you were related to probably lived within a day or so of you. You had enormous support networks. Now we all live in these little isolated brick cells with neighbours all around that we wave to, but who aren't much help in times like this.
If you don't look after yourself, and blow off some steam, you end up becoming someone your wife and kids don't need, cranky, depressed, stressed, sick etc.
Time to get on the phone!
If there's anything I can do to help let me know.
P.S
I was all set to go to the big brew day at Fatboy's tomorrow, but I have to look after my 3 kids as my wife is away for the weekend. If you want to drop round for a beer (with the kids) over the weekend, PM me.
Matt