Morticia, I write from personal experience, you have to accept that everyone has a right to choose their own destiny. Nothing, absolutely nothing you could have done could done, would have altered events. They may may have delayed events causing more grief for David, which from what I read above is the last thing you would have wanted. I saw the pain my parents went through, blaming themselves for things that were outside of their control. Rest assured that for someone to take, what we perceive as that extreme way, to end their own life, that they are now much happier and contented. All the pain and suffering they experienced has now ended. Sleep well. Love to all