The point about feeling drained when the startup is failing, and feeling energized when you hit something people wants is spot on. My startup failed (as most do) and since it happened I've felt that I was not made for business. But recently I watched how my brother hit a strike with his company (still small but people is super interested) and I see how that keeps you much more energized.
Maybe I'll try again soon, but this time I'm starting really small till it takes traction on it's own(another usual tip I didn' listened the first time...)