Gidday Gearup'.
39, no debt and house paid off! Well done, but therein may lie the problem.
I was 30 when in the similar situation to yourself, at least hours and career wise. A supportive wife (at the time), no kids, and the absolute arse out of our pants. Back then unless you had the mins for the airlines by 25, you weren't going anywhere. Times have however changed. My wife finally called its quits some years later and on my own with lots of networking, no real lifestyle, and a smattering of luck, I managed to crack a series of gradually improved GA jobs. 9 years later, right place at the right time, jagged the big one. First officer Regional airline, $32K PA!
I have since remarried, 2 children, house in a nice suburb, even an SUV in the driveway. Despite a good income, I doubt that we will ever have our house paid off. one of the prices I have paid. I absolutely love my job. I look back all those years and honestly feel it has become the career I always dreamt of. But as I have said, at a price. If I could do it all over again, the one thing I would have done is to kick it all off at 18!
The point I'm trying to make, is about reality. While never letting go of the dream is essential, you probably might have to ask yourself, at 39, was my dream, financially irrational as it is, strong enough to become a reality.
I hope I'm wrong, but you may have to admit, you might have missed the boat!