Entrepreneur ;-)
But first, do you want to become a specialist? Or would you like to stay a generalist?
I wouldn't force a fit. I'm dealing with the same situation actually.
I realized that in a specialized society, a generalist is a specialist. You're a generalized problem-solver. You're not just adding new knowledge and skills, you're integrating them.
It's hard to explain to others what you're good at. And sometimes you don't even know yourself. But that forces you to follow your own vision.
As to being an entreprener. I agree that it's an excellent fit . . . although I realized recently that my talent lies in support and refinement of people and ideas. I am not much of an idea man myself, to be honest.
People have a tendency to define themselves in the static. But people aren't static they're dynamic. The hardest part is refining who you are, so it makes sense to others.
You have to create your career.
Unfortunately, I don't think I can give anything more than general advice (in principle). But I can relate to your situation. It takes a lot of thought and experience to figure out how you're going to do anything new.
But communication is essential. Consultants seem to be hired, often because of their writing skills. If you choose to go down that route.
EDIT: I'm self-taught too. I think it's a common problem for us, that adds to the complication. You can't point to a degree. And I have no special skills. But that's the trade off I wanted to make.