Coping with someone passing

I’ve never had to do this before... wait for someone’s death. Being scared for the day you get the call. My grandmother has been battling cancer. Hospice told her she might have 1-2 weeks. What do you say? what do you do? I have no idea. I’ve had deaths in our family but they weren’t something we were expecting. My grandmother on my moms side passed away in her sleep. This feels different. It’s the sad waiting. It’s the feeling of wanting to hold on and never let go. It feels unreal. For the first few months of her diagnosis I was in denial. I thought she could beat it and she would have many months ahead of her. All of this happened so quick! 6 months quick. Do I tell her everything I want to say? Do I pretend to be okay and not cry? There’s so many tears and feelings and all of this just hit me today. When I heard it’s only weeks left. I’m supposed to be taking my board exam soon and I really wanted her to make it to see me pass. She was always one of my biggest supporters. Even in ways where I didn’t notice. I don’t think sad is even a word to express the situation. I wish there was more time left but I don’t want her to be in pain anymore.