Nuance Dictionary / Relief & Freedom
홀가분하다 hol-ga-bun-ha-da
Feeling physically and mentally light, entirely free of worries or baggage
Very similar to '후련하다', but '홀가분하다' emphasizes the *lightness* of your state. Imagine taking off a 20kg backpack after hiking all day. That physical sensation of weightlessness, applied to your mind after quitting a toxic job, is '홀가분하다'.