Have you considered starting something in your wheelhouse? If you worked in oil and gas for six years, you probably know that space cold. I don't know much about it, but I'm guessing there is lots of money in it, and it has room for further disruption by technology.

If you take time to learn programming first, you may miss the current window of relatively easy seed money. Think of an angle, use $40-50K of your nest egg, and get a contractor to build a nice prototype quickly.

If/when you do go out to raise money, you'll have far more success if you can tell a convincing story about why you have an unfair advantage in your chosen space. Leverage your history and experience to its fullest; that's something others cannot compete with you on.