I had to go through all you say Louise. I can safely say that I got out to the other end and I am a lot happier now because I allow myself to be kinder to myself because I have thrown all expectations over board.
I realised that, as you say, nobody is responsible for the fulfilment of my expectations and that whatever happens in my son's life is none of my business. It took me the best part of ten years and many painful moments but I get it now. Do I wish I had got it earlier? Not sure because the whole process belongs to my personal development.
I wish you well, Daphne. There is a world out there beyond being a grandmother. And who knows the ability to explore new ventures may make you interesting to your grandson when he is older.
Thinking of you.