To be fair, OP's speed of progress involved aptitude and diligence, even if you discard smarts. It's true that when you work five years at a code base, you probably become an authority in it because at some point it is yours too, but I've known developers who would never achieve that state.

That being said, tech megacorps are stressful environments, and OP looks like he has his plate full just accepting that he's become the de-facto lead developer. OP built his own niche market, why not dial it back a bit from eleven and learn to enjoy it?