Dotsie, Having no children to leave home, I probably have no way to truly commiserate here. I know it's a bombardment of loss for you, and I can only imagine the pain of feeling those threads of connection stretching farther and farther away from you.
I do have one niece who has been an integral part of my life for the past 18 years. We're very close. As we keep having to postpone this year's family reunion becaue of my brother's cancer, she's just informed us that this year will be her LAST family reunion for awhile. When she finishes high school in June, she's planning on going to China for a few weeks and then to Africa indefinitely to do some missionary work (through her church's missionary agency.) The thought of not having her around at family gatherings and Christmases anymore just rips at my heart! So I have a small inkling of how this empty-nesting feels, albeit at a much smaller scale than a Mother.
When you don't like a thing, change it.
If you can't change it, change the way you think about it.