Sue, I'm sorry for your loss.
I had to arrange several funerals etc in a short space of time.
Start by deciding what needs to be done before the service, and what doesn't.
It sounds like you are falling over what I call The Cliff of Tiredness, or swimming through porridge.
This is normal, so is being really forgetful.
Write a list of everything that's worrying you. Shuffle it into order, and ask us "how did you...."
The forum isn't just for current carers, but for former carers too.
If, like me, you just can't sleep, tell your doctor. I was too stressed to sleep, but desperately tired. I had some gentle pills to help me relax, and fall asleep. Gradually I reduced the dose without any problems.