What idioms are there to describe letting go?

There is only one idiom to describe letting go: relief.

Pinyin: rúsh zhòng fù

Interpretation: release: put down; A heavy burden: a heavy burden. As easy as putting down a heavy burden. Describe the relaxation and happiness after the tension has passed.

Source: Twenty-nine Years of Gu Liangchuan Zhao Gong: "When Zhao Gong came out, the people breathed a sigh of relief."

Example: My sister breathed a sigh of relief. ★ Qu Bo Lin Xue Hai Yuan