I hope your son realizes we all make mistakes (including him) and that he finds it in his heart to forgive. Your grandchildren need to know you and vice versa. I truly hope it all works out for you. My dad and I were estranged even after I repeatedly attempted to reconcile and he died without ever meeting my children. So sad.
[ What is life? It is the flash of a firefly in the night. It is the breath of a buffalo in winter time. It is the little shadow which runs across the grass and loses itself in the sunset. - Crowfoot, 1890, on his deathbed. ]