她因对朋友说了刻薄的话而感到深深的内疚。

She felt deep ___remorse for saying harsh words to her friend.

他对自己过去的错误行为深感懊悔。

He felt deep ___remorse for his past wrongdoings.

他因对朋友说了刻薄的话而充满内疚，整晚无法入睡。

He couldn't sleep all night, overwhelmed by ___remorse for the harsh words he said to his friend.