I'm annoyed because I have to take care of my grandma who has dementia.
Why do you find your grandma annoying?
She didn't do anything. I'm just tired of her neediness.
I understand taking care of family can be frustrating, but you need to be supportive of family members who need it. Your grandma would not be able to get by without your assistance. Think about how much of a positive impact you have on her life by being there to help her.
Fuck her. She's ruining my life.
I'm sure the situation won't last forever and you'll miss her when she's gone. It's best to just support her while you can.