oh sweetie~ i am so very sorry you are going through this, I really am..It is never easy! I am not sure what kind of diagnosis you have. Coping with cancer and your feelings and the emotional roller coaster you are feeling is "normal" considering the circumstances. Soon enough, you will come to grips and do what you have to do to go through this. Remember one thing; that this is a journey through life that you are going through. You are passing through this life and we all are. No one knows what the future brings for any of us, but rest assured, that if you have Christ as your savior, then you will come to peace with yourself and others will follow.
It is very hard for your family too. They are at a loss for words and sometimes they even say things that make no sense at all. I was there where you are at one time in my life. (several times) if truth should be known. Not all due to cancer. I am not sure what your religious beliefs are, and it is none of my business. I am not here to preach or judge, I am just here to offer my support to you and if there is anything I can do to help, please feel free to message me.
I am very sorry for what you are dealing with. May I ask what type and stage of cancer you are at?