So sorry you're going through this. My Dad passed away at home, from cancer. I won't pretend it's even nearly the same thing, but some practical advice....
Draw a small number of friends/family close. Let them come and help and support you.
Be prepared for lots and lots of friends/acquaintances to want to come to say their goodbyes. Don't be afraid to say he's not feeling up to it today, if he's tired or you just want the time to yourselves. (Especially if it's someone he hasn't seen in 20 years, who's only coming to ease their own conscience about letting a friendship lapse.)
Someone mentioned doing the 'admin'. I found this a great help. Get any passwords, account details etc you need. It's morbid, but it's realistic and practical. And in a situation you can't control, it's doing something positive.
As you're married, I imagine you don't have to worry about legal details such as wills. I assume everything passes to you, but probably better to check with a solicitor, and avoid any drama down the line.
Have a (brief) discussion about the funeral. Mostly for us, this was just confirming that Dad's wishes were what we expected they would be.
If he's religious, ask a priest/reverend to come and talk to him. My dad was elderly and this was vital for him. As I'm non religious, I almost forgot this detail, and only remembered when a relative mentioned it.
Try to get some outside help for the nights. Cancer charities might be able to help with 'night nurses'. Otherwise, lean on friends and family. Try to sleep yourself.
There are no right or wrong ways to go through the next few weeks. It will be hard, but you will be able for it. Sending you love, best wishes and mountains of courage.