A manner adverb plus 고치다, which stretches over repairing an object, revising work, correcting a habit and treating pain. Six of the eight lines use the pointing adverbs meaning how, this way and that way: how did you fix it, I fixed it completely, revising and revising until it ran late, a clinic that fixes those things so they hurt less. Keep it apart from 낫다, which is something getting better on its own.