to be both mentally and physically exhausted (idiom)

to be completely drained both emotionally and physically (idiom)

worn out in body and soul (idiom)

to bend to a task and spare no effort (idiom); striving to the utmost

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