I say, get a babysitter if you can - take her out & enjoy her once a week. A hotel or even a motel quickie will stop her complaints if she doesn't have to have two kids constantly around her. Sex is the last thing on her mind because she's giving all her energy to the kids. Take her out - take your time - remind her what sex used to be before there were kids, she'll remember to enjoy herself with you & use it to lure you away from the computer
My mother always said: Better the devil you know than the one you still have to figure out.
Changing the woman in your life will not help you one bit - other than the sex part, you'll still have the same responsibilities with double the costs.