How to let go the past?

Mom Has six months to live. Pancreatic cancer. Now she is nice. If only she had been like this years ago. Why does it take impending death to make us realize we are going to die and we should love each other every day of our lives?

She seems surprised we are all rallying around her. Of course, we are nice people. But she is not. Has been hurtful in the past. Wasted many years being spiteful and vindictive. What a waste.

I am having a really difficult time dealing with the change and knowing she should have been this ways for years. Especially toward me.

How many of us think we are living forever? How many know to love everyday?