Oh, Sweetlove. BIG HUGS to you.....
I still have not fully grieved for the sudden death of my father, feel guilt and torture myself for things relating to his death....so I can relate to what you're going through, and it is utterly gut-wrenching.
I have not worked through this in my therapy yet, but during the times that I've touched on it in therapy, my T told me similar things - about torturing myself and trying to control things or take blame for things that are completely out of my control.
It's so hard to let go....I hope to be at a place someday where I can willingly let go. The thought alone hits me at the core in a painful way, so it's hard to imagine.
Giving you big hugs, Sweetlove....