Go home and tell your wife you have an idea, something you would like to try with her.
Tell her you want to plan a nice evening out for the two of you very soon, one that at some point in the evening will involve you making love to her, but that you have no intention of making love to her at home after the date it through. Perhaps in a motel, perhaps in the car...but someplace different than at your home. Tell her to think about it, and let you know in a few days what she thinks about your idea.
If she is game, then plan a date for your wife very soon. It does not have to involve a lot of money, but doing something other than the typical dinner/movie combo. On a weekend night, if possible.
Tell your wife a week in advance when your date will be. You tell her what she must wear, but not where you are going and what you will be doing.
Then plan. And see how it goes.
Perhaps because of your wife's stresses and children, she does not see herself as a desirable woman in her own home, hm? Perhaps she can only feel like a wife and mother at home, but not your lover.
It is not written anywhere that the only place we can have sex is in our own homes. It is convenient, yes. But if one cannot get the needed sex in one's home, then maybe one has to leave the home to get what they need.
It is not always convenient, and it does not always work, but I'm sure most would be willing to pay for a babysitter for a few hours each weekend if it did in fact work.
It is a suggestion, nothing more.
I also agree you should consider seriously visiting a counselor.
