You've got to stop kicking yourself. It wasn't your fault that the project failed.别再自责了，计划泡汤不是你的错。

He was kicking himself for having forgotten the meeting.他因为忘记开会而非常内疚。

He could have kicked himself [=he was very angry at himself] when he realized that he had forgotten the meeting.当他发现他忘记了开会时，内疚得要命。