I'm sorry you're having a rough time lately - you know, like the last 9 months. Ditto asking for help - sometimes we only need a couple hours. I was having one of these moments not too long ago, and my mom showed up at my house and made DH and I leave for 3 hours - seriously. She told us not to return before 10pm because she wouldn't let us back in. We sat at a restaurant for 20 minutes (and downed a glass of wine each) before we were able to start talking to each other, we were so fried. It wasn't until after I was able to start relaxing a bit that I realized how much I needed the break.
So - moral of the story: if you have someone who can take the kids for a few hours, jump at the opportunity. Go get a pedicure, sit in a coffee shop and sip a latte, read a book, whatever you need to unwind and come back refreshed and ready to hit it hard again. And good luck!