The English is pretty good but the word choice makes it seem stiff and unnatural. I don't scanlate so take my words with a fistful of salt, but try recreating the sentence's meaning in English instead of translating phrase by phrase.
For example, "Falling. Falling. I'm falling!" It sounds so awkward. No one will say that, maybe in Japanese, Idk, but I speak English and I wouldn't say that.
If I were to reform this sentence I'd make it, "Huh? Wait, I'm falling!" This can flow out of the tongue much easier. It's not the precise translation (probably, maybe) but it still convey the same intended effect, right?