writhing in agony; tossing about in great pain; (figuratively) to be in extreme distress
腹痛で七転八倒して救急車を呼んだ。
I writhed in pain from stomachache and called an ambulance.
彼は借金返済のことで七転八倒しているようだ。
He seems to be in agony over how to repay his debts.
手術後は痛みで七転八倒したが、やがて落ち着いた。
After the surgery I writhed in pain, but eventually settled down.