I'm not going to speak to my grandmother anymore
Why don't you want to speak to your grandmother anymore?
There are several reasons why I don't get along with her.
It is understandable to not get along with everyone in your family. But because your grandmother is old and won't be around forever, you should make an effort to get along with her while she's still here.
It doesn't matter, I'll be fine if I do this. The feeling is mutual and she know's she needs to leave me alone.
I am sorry you feel that way, I hope you do speak to her though. When she is gone you may regret this decision and will never have closure.