couldn't be helped, had no choice
従うよりしかたなかった。
I had no choice but to obey.
社長命令だったんだからしかたなかったんだよ
It was an order from the president, so I had no choice.
— Departures (2008)
「今思えばしかたなかったことかなとも思う」→
Looking back now, I suppose there was nothing I could do about it.
— 映画 聲の形 (2016)
彼は早く娘に会いたくてしかたなかった。
He couldn't wait to see his daughter.