Being self employed I can relate. The bills are piling up and the money is not coming in. I still go to the office just for a sense of normalcy but the truth is I don't know what a hit like this will do. My budget is month to month, if I do not earn money I don't get paid.
My wife is worried sick over it, but I just carry on. The nice thing about being self employed is that in the past 20 years, I have seen good times and I have seen hard times yet through it all I am still standing. The hard times always seem to end just at the right time.
Take a deep breath and enjoy the day with your children!
Happiness is a choice regardless of the circumstances.