I feel bad for you right now. It's a bad time for this to happen.
I don't know what your own work sitch is but nonetheless you can't be expected to do it all yourself.
Why don't we turn this around here. You're not f'd. He is! You were about to get your utilities turned off and he promised you vital $ by Friday. Now it's not happening for 30 days?! Tell him to step it up, Dad! Get out there and hustle something up. Temp. Shlep boxes. Sell something. Whatever. Get some income now and support your children.
You've got a lot of weight on your shoulders right now. Load some of it off to others so you can stay strong.
Call your L now and tell him/her this situation - you don't have to start a whole D, just tell him/her what's going on. This isn't right. L might be able to help in some way or guide you to resources and assistance.
Ask for help from friends, parents, etc.
You WILL get through it.
"My actions are my only true belongings. I cannot escape the consequences of my actions. My actions are the ground upon which I stand." Thich Nhat Hanh