Sticking to one thing is overrated :)
“I believe in bumbling around long enough to not give up at things. And eventually success comes your way, because you tried to fail in every possible way, the only way that’s left is the one successful way, and always, for entrepreneurs, seems to come last." - Vinod Khosla, cofounder, SUN Microsystems
Just a couple of feel good books disguised as pop science to quickly read through ..
* Cal Newport's So Good They Can't Ignore You on the value of skills over passion and identifying what makes you valuable to others (instead of what you think), he defines "competence" as "feeling that you are good at what you do." It's a good overview of skill acquisition.
* Little Bets by Peter Sims will give you the grace to reframe your "jumping around" as a series of "little bets" of "discovery" and "inquisitiveness", not based on a particular skill or talent but on problem solving and interest, a curious, restless displeasure with how things are. A great book for wandering professional souls.
So my vote is keep jumping around, find interesting problems to you and work on them, develop some methods of having your competence evaluated by others, join (or lead!) "professional communities" to find and commune with likeminded folks, stay restless and hungry.
If on the other hand you really want to focus on one thing, sign up for a modestly expensive professional exam in the not too far future and an obligation to teach or share what you have learned for that exam publicly. I find it's a great motivator to be beholden to others to understand something well enough to motivate others to learn what you have.