to bend to a task and spare no effort unto one's dying day (idiom); striving to the utmost one's whole life; with every breath in one's body, unto one's dying day
身心交瘁身心交瘁shen1 xin1 jiao1 cui4
worn out in body and soul (idiom)
神劳形瘁神勞形瘁shen2 lao2 xing2 cui4
to be completely drained both emotionally and physically (idiom)
心力交瘁心力交瘁xin1 li4 jiao1 cui4
to be both mentally and physically exhausted (idiom)