This is horrible for you. I have been there.
This story might help you... It certainly helped me!
My dad died. He had an enlarged heart and eventually it just gave out on him, after he had a stroke.
Incidentally a colleague helped me. Entirely by accident. She is a lovely girl but incredibly dim.
A conversation over several days when like this:
"Good morning, Matt. How is you dad?"
"Thanks for asking. It's not looking good. The hospital tell us he only has a couple of days left, at the most."
Next day:
"How is your dad, Matt?"
"Sadly, he died yesterday."
"Oh! I am really sorry about that."
The day after:
"How is your dad, Matt?"
I looked at her, another colleague looked like she was going to punch her, until I said: "Uhhh... thanks for asking, xxxx... but he's still dead!"
And I know that I heard my dad laughing. And I knew things were going to be OK.
Years later when I reminded my colleague what she had said she looked horrorstruck and said: "Jesus! Oh, I am so sorry! Talk about a blond moment!"
She is a natural blond and lovably dittzy! Like when she said she hated Rome as there were far too many Italians there!
You will get there, to a better, happier time. But it does take a while