Thanks for posting. It sounds as if you have been through so much, but you are still making it and still getting up every day (even though you don't want to) and that is a good thing. You don't mention whether you have tried cognitive behavioral therapy, but many people have found this to be helpful.
I hope all is okay with your daughter in law. I am sure they appreciate your support and know that when you are able you will be there to help.
Eileen