For Yippie Skippie, I can sympathize that being a stay-at-home parent is AWFULLY unstimulating intellectually, and lonely. Even if you try to network with others doing the same thing, many of them will be unable to carry on anything resembling a thoughtful conversation. It's just plain horrible.
To keep your sanity, as well as a positive affective tone (i.e., being happy), you MUST find some sort of outlet and way to get out on your own with simpatico people. Is that going to be hard? You bet! Maybe it comes down to a book club or an online chat community on a topic you enjoy. I also agreed with someone else's suggestion, that you get into advanced studies or another more challenging milieux, - but it's not compatible with your current primary occupation.
Maybe writing a book about your current situation would be something you could work on, over time? Also, joining a writer's group might be a good place to come out of the close about being smart.