Should I run my own business?
When this is a valid option, it is always the best choice.
If I had to choose a completely new career I would neither go into software development nor into the law business.
Unless you write games and/or run your own little software business with your OWN products, SD has become extraordinarily boring and uninteresting.
As a lawyer, these days your only chance of survival is working for a big law firm. The days when you could survive as an independent lawyer are over. I don't know about you, but I wouldn't want to be just another suit in a big office building filled with hundreds of other suits.
I believe that there is a lot of money to be made in genetics/bio-engineering. But you'd have to go to a country that does not ethical laws preventing research on the human genome. In other words, you'd have to go to China or another Asian country. No matter what you do, you should add Mandarin to your list of "foreign languages to learn".
Becoming a Medical Doctor never was a bad idea, either. You could work ANYWHERE in the world, especially the Scandinavian countries still have a high demand for medical staff. And they pay well.
Since this is an Apple forum, you should search on YouTube for Steve Jobs's famous Stanford speech: "You've got to find what you love. Everything else is secondary."
It's a lot easier to make a living when you love what you do. All the money in the world does NOT compensate you for a boring, brain-killing job. Believe me, I've been there more than once. There are only so many toys that you can buy, and no toy is a substitute for happiness. And money almost never is a primary factor when it comes to happiness.