Aging parent slipping away

How dose anyone ever get through seeing their parents get older and less able than they used to be?  I am having such a hard time watching my mother's health go down and knowing that it probley won't be to long before she is gone.  I sit here and cry and think no God no,.... please I am not ready for you to take her..... please no!  I treasure the moments we get to spend together.....and try to make them extra special for her and me too....creating good memories (memories worth more than gold).  I just for the life of me don't know how anyone gets through this stage of life that is so hurtful.