Hi guiltier
I'm sorry you're struggling so much right now

And maybe you have a lot of "Should have been able to..........Could have's........Would have's............Wish that I could have been better/could have changed things" going through your mind right now??
But you know some things are completely beyond ours (or anyone's!!) power, sometimes things happen that we, or no-one could ever prevent........but that doesn't make us weak, that doesn't make us failures..........that makes us
human 
It can be much more about doing what we can, where we can remembering our limitations and showing ourselves compassion when it comes to those.
And I know that you have absolutely tried your best
so many times e.g. with your grandchildren and your son/daughter, in fact your insight and caring has been completely
admirable!!!
So please try to give yourself some of that praise you're due, and some of that compassion you
so clearly show to others, you deserve it!!!!
Alison