Have you ever had a moment of trembling inside? What is it like?

I remember 12 years, my grandfather fell ill and lived for a long time. Later, he recovered and the whole family was very happy! One day while playing in bed, I suddenly found a suicide note under grandpa's pillow. The arrangement for future generations was neatly written on the yellowed stationery, which finally mentioned: Therefore, children must be filial to my mother and must take good care of them ... At that time, my heart was shaking and I was so sad! Grandma is his only concern when his life is unknown.