To see it end like this is devastating. To see the damage done and how helpless you are is unspeakable.
I could not agree more with this. I watched my grandmother like this for many years through the eyes and stories of my family. I did get to fly out and see her a few months before she passed and she had one of her only clear days while I was visiting. The others were an absolute shit show. She was in a constant state of panic and confusion. It broke a little more of my heart seeing her like this. She was my last living grandparent, the rest had already died from cancer.
I can say honestly this was the worse way to watch a loved one go. Scared and alone after such a full life is just wrong. I wish there was something I could say to make this easiervbut I think facing it head on and accepting it is the best course of action. Explain what you can to your boy and celerbrate the good positive moments all you can, it all ends in the blink of an eye.