You are not to blame for what has happened to your family. This is a journey your h is taking to find himself and to face the demons of long ago. There was a piece of him that really didn't mature w/the rest of his "self" and that's what needs to be re-evaluated at this time. Please, do not blame yourself. Why? If there had been an issue w/something you had or hadn't done, he should have told you and not leave you in the dark. After all, we are not mind readers.
Be kind to yourself and know that you are a very good person and never question yourself about that.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.