My mother's helper's name is TV.
That and you could give this a try, it worked some days better than others for us.
Have an afternoon quiet time. Read a book or two with the kids, then set them up with a movie or on the computer on pbskids.com or whatnot and you lay down with the baby. I got really good at sleeping with "one ear open".(like if something happened, I could intervene, like, you know, if someone cried and it was obvious they needed Mom, otherwise, I napped) I figured whatever needed cleanig up after that nap was worth it, and I did have a bag of flour get knocked over, but, hey! Flour is cheap and gets cleaned up, and it is worth feeling saner after 30 minutes sleep.
Do what you need to do to get through this, it gets better!