I missed my calling :(

I am almost 38, married w/ 3 kiddos. I have an MSN in nursing admin. Like most people, I've had jobs I like and jobs I don't. But I've never had one I love. And now I've gotten to the point that I hate my current job, but I feel trapped in it for various reasons. I've thrown around the thought of going back to school to become a midwife for a long time, and I so wish I'd done it years ago. It makes me sad when I think about it. I just feel like it's no longer a realistic option for me because of my family commitments and my age. Plus I live in a rural community, and there would be no guarantee of work. I struggle with those thoughts so often. Anyone else feel like they missed their calling?