If you haven't watched this, please do. I guarantee it will help with both motivation and confidence.
That's me on the cover of the DVD. Watching this documentary is your initial homework. Then, watch it again every time you're in need of inspiration. It's about runners over 50, but the message is critical for everyone because even people half that age need to see where the fitness provided by running will take them - can take them - in the years to come.
You'll find it on Amazon, YouTube, and Apple.