Trin -
Lovely lady, you have that pizza, enjoy it, make the most of the sunshine and the girls being outside. So what if you kept them off school, so what if you can't be arsed today? So what?
These next few weeks and months are going to be filled with days when you will feel like saying/screaming/yelling out loud 'FUCK IT'!
To the world outside of your sanctuary, to school, to getting up, getting out, eating, washing, doing the housework, moving from the sofa, etc......... you know that sweetheart, how I wish with all of my heart that you didn't feel like that. 
BUT, there are going to be days when you'll more than make up for that by kicking ass out of the housework, getting the girls to school, sorting the bills out, food shopping, mowing the lawn, sweeping the path/driveway, cleaning things up, showering, looking at yourself in a new, brighter light, something new maybe, because it feels right to do that, whatever 'that' may be.
You'll ebb and flow with the grief that you are enveloped in, you can't help it, no-one can pull you out of that..... only that old cliché time will ease the severity of how you feel on the down days.
May hay when the sun shines. And, when it pisses down, take solace in your sanctuary. :)
Have you managed to get your SW back on board? How are the 'practical' things?
Big hugs to you gorgeous xxx