It is obvious that you have poured out your heart to your mom in her loss, yet your sorrow for your grandmother's passing is vivid as well.

In truth, the poem speaks volumes of your realization of your own mother's mortality. In your comforting of her on the loss of your grandmother, you presage the very things to which you will take to heart when she passes.

You have attained wisdom through anguish - such is the human condition. Wonderful expression of this experience.