I'm going to silently get up and walk away when my grandma sits next to me
Why do you want to treat your grandma like that?
I'm tired of her telling the same stories over and over again, she just keep saying things about my brother who died of drug overdose.
Your grandma just wants to spend time with you with the limited time she has. You can't just shun her like this, it's rude and devastating. You need to be with her as much as you can.
I'm tired of people talking about my brother and my grandma won't understand it.
Even if it is difficult to talk about your brother, you can't shun your grandma. She is family and wants to spend time with you.