I gotta ask: why?
She says that she "can't stop"... but why? Why is that the case?
"...Did it really all come back to power? She was still so very small and weak. Her path still stretched on, infinite and difficult. There was so much more distance left to run."
Why do you need to go further and further? Why does it all come back to power?
If you have enough power to achieve what you want, and achieve security, then... that's fine, isn't it. It's like money or riches in the real world; you get enough for security and happiness. But you don't make a religion out of pursuing it. You could reach for more and more wealth and/or prestige and/or whatever, but at that point, you're basically just keeping score.
But you've convinced yourself that you're always in danger of somebody rolling over in their sleep once and upending or demolishing all you've ever built. You see a world full of supremely strong people, and you fear that this means that you can never know enough security, and so you tell yourself that you need to reach further, reach higher, and never stop moving.
But I think the truth is, is that even if you ascend, that uncertainty and danger won't go away. Because even if you become a Top Dog somehow, you'll still have risks and dangers and challenges and problems anyway. Maybe you'll be more secure, but at the same time, you'll also have to play the game for eternity; because you'll be ageless and immortal. At least as a mortal, or even a cultivator, you'd be able to die of old age and pass on and be done with it all.
So, all in all...
I'm not sure why "it'd break you." I mean, maybe it might now.
Because Ling Qi is a literal teenager and is still suffering from insecurities and issues galore.
But, like... How much has Ling Qi actually went back and re-examined the age old motivation for why she began this? That is, looked at Cultivation and her advancing forwards asked "Why?"
I think Cultivating because of a "from", as Rincewind would put it, is different from Cultivating because of a "to". Don't Cultivate out of fear, not forever, but do Cultivate towards a positive goal or for a positive reason.
And, frankly, know when enough is enough or when/where you need to/ought to stop, too. -_-
This, on the other hand, feels like a better reason to advance. Advance so that you can keep up with your friends and comrades; the people you've befriended and decided you want to stick around with.