Some of you pointed out in your comments that deep down, I know it's not evil to feel the way I do. And you're right. I do know that. What was really getting me was not wanting my mom to know I felt this way, because the one time in the past I said something similar to this, my mom got really upset.
Mom and I had a conversation yesterday. Granny was looking worse; now they think she's had a stroke. As gently as I could, I asked if Granny had a living will. Mom said she'd never been able to find one, but we do have a Do Not Resuscitate order. That kinda opened it up. I asked, again as gently as I could, if Mom thought that Granny would ever leave the hospital. She was noncommital, but didn't seem to think so.
We both started crying. Mom ended up saying pretty much the same things I said in my entry. She said, "I'll miss her... but I've been missing her for ten years."
Then we talked about the mundane, but inescapable, details. I asked if she needed me to come home, and she said not yet, but to check and see if I get bereavement leave. In an odd way, that was the phrase -- "bereavement leave" -- which brought it home the most.
Big thanks to atomicnumber51 for talking me through a lot of this. The best part was when she got me telling stories about my grandmother and she said "Wait, is this the grandmother you get your snark from?"
She's up and down a lot. The yo-yo nature of it is horrible. I just hope it's over soon.