心如刀绞

xīn rú dāo jiǎo

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

心

xīn

heart

如

rú

as

刀

dāo

knife; blade; single-edged sword; cutlass (CL:把[ba3])

绞

jiǎo

to twist (strands into a thread)