心如刀绞

to feel a pain like a knife being twisted in one's heart (idiom)

heart / mind / intention / center / core / CL:顆|颗[ke1],個|个[ge4]

as / as if / such as

knife / blade / single-edged sword / cutlass / CL:把[ba3] / (slang) dollar (loanword) / classifier for sets of one hundred sheets (of paper) / classifier for knife cuts or stabs

to twist (strands into a thread) / to entangle / to wring / to hang (by the neck) / to turn / to wind / classifier for skeins of yarn