I'm sorry to hear you are going through a difficult time.
Grief is a very hard thing to deal with, and no matter how prepared we may be, it's never really enough.
It's difficult as well to take care of an ill family member, it's emotionally and sometimes physically draining.
Deal with it as best you can, but don't let it overwhelm you either. Remember that you need to take care of yourself as well.
Try to get some help through your hospice, and try to get some grief counselling. It does help put things into perspective, when we can't find any.

My sister passed away a few years ago. She had been ill for a very long time, so we were prepared for everything, although it still wasn't easy for anyone. My brother passed away last year, and we were not prepared, so it was a lot more difficult. I took care of both of them while they were in the hospital, and I know that your loss is greater when you suddenly stop the caregiving and you must continue on with your own life.
I spent a year grieving and making myself sick.
Therapy helped me focus and move on when I couldn't.
Just remember it's okay to mourn your loved ones, but don't forget you must still go on with your life too.