Cannot imagine your pain. Dad died at 63 (pancreatic cancer) and I thought I'd NEVER get over it. Took years, but I'm ok now -- with wonderful memories and stories that my siblings and I share with laughter on the holidays. It DOES get better.....eventually.
My mom is 80 and I cannot imagine what I will do when she is gone. Something about the relationship between mothers and children.
I would agree that at least you have time to say goodbye -- small comfort, I'm sure. I've often thought about the way we die -- if it is sudden, it is often easier for the person who dies, HARD on the family. Of course, death is ALWAYS hard on the family..............perhaps it is a matter of degree???? Shock versus grim resignation.
So very, very sorry. You both will be in my prayers......especially praying for GOOD drugs to keep your mom out of pain.
(((HUGS)))