You described my own situation almost perfectly: Late 20s, self taught programmer, good amount of professional experience, right down to building a compiler in my spare time. My motivation towards programming has always been mathematical abstraction, rather than engineering. Some time ago, I decided that I need to either a) get payed to work on whatever I want, whenever I want, or b) get a job that isn't mentally taxing, and keep programming on the side.

I've picked b.

I'm about to leave my job to take a 12 month volunteering role in SE Asia, with some small web-development contracts to keep me going. It will give me time to think seriously about the future of some side-projects, and generally, about what I want to come back to.

I'm certainly not saying that this is what you should do, but just that it is an option.