Cancer is a dark entity

My dad diagnosed in January is now end stage mesothelioma. Weeks to live. The last month I've felt like the cancer is a 3rd person in the room. I can't get through it or round it and it's in my path of any plans I had. It's even got a voice now. My dad's personality has changed. He yells "leave me alone'and 'no' all the time to even the basic levels of care to keep him clean and dignified. It's claimed his mind and character. It's like an existence of its own and I hate it like I've hated nothing in my life.

I'm now praying for him to pass. I never thought in a million years I would ever wish this on my dad. But cancer has consumed just about ever around him and us. Is this normal to wish this upon one of the most loved people in my life?