Figgy, I think that the "lack of fulfilment" of which you complain is endemic in our society. Unfortunately, I think the solution to it is not very popular . . .
You see, we live in a society and culture where individualism has been elevated into a sacred cow, a "golden calf" if you will. We're taught by everything and everyone around us that "I'm OK, you're OK", that "self-esteem" is important, that "fulfilment" is paramount.
Now, take a look just a couple of generations back. Did the Great Depression generation feel "fulfilled" when they managed to get just enough work to put a meal on the table - with no guarantee that they'd be able to do the same tomorrow? Did the farmers in the Dust Bowl feel "fulfilled" when they trekked hundreds or thousands of miles across the country to take menial laboring jobs, just to feed their families?
Go back further, and the same picture is reinforced. It's only in the past two generations that this ridiculous "self-esteem generation" thing has come to dominate our thinking and culture. It's a fraud, and a monumental one at that.
I suggest that our "lack of fulfilment" is precisely because we've come to focus inward, on ourselves, rather than outward, on others. I'd say that with a wife who loves you (and her love is hopefully returned!), with kids who are relatively balanced and "normal", with an adequate income to support you all, you're doing pretty darn well - certainly better than well over three-quarters of the people on this planet.
If you're looking for more "fulfilment", why not try social service? Volunteer - by all means through your church, but if they don't have suitable programs, through a faith-based organization like the Salvation Army - to help those who are worse off. You'll find feeding, clothing and helping the needy is a pretty fulfilling thing - and will also help you to appreciate the sanity and balance in your own life and family! Try helping out with Habitat for Humanity to help the homeless. Try getting some counseling training and working with an organization that mans phone lines for use by those in a crisis situation who need someone to talk to.
I find that if I focus on myself, I get minimal "fulfilment". If I focus on others, I get to help those who need it, I'm reminded of how fortunate and blessed I am, and I can do something that all too few others are willing to do.
Just my $0.02 . . .