Danialla
I've heard grandchildren are a special bunch. Thanks to my son, my father managed to survive lung cancer for a total of five years. He lived for that boy.
When my son was around your granddaughter's age, I was sitting with my father and we were admiring my son playing on the floor in front of us. My father thought my son was perfect and could do no wrong, lol. He said to me "You know that overwhelming feeling of love you feel for your son? It never goes away - it just gets stronger. That's how I feel about you."
He then went on to say that parenting is very hard, but grandchildren are the reward for enduring all the headaches of parenting.
I hope your son can find a way to move back closer to you. I'm sure your granddaughter is also "perfect."