RE: To those who have lost a loved one to illness/cance...
I am so sorry to hear that you are going through this. I too went through the exact same thing.
I will quickly tell you what I learned from my experience. First of all, my father didn't want anyone helping him either, it's a pride thing. A father is the beacon of the family, for him to be helpless is a very difficult thing. My father didn't want anyone except family seeing him in his final days. My mother never left his side. I struggled a lot. There were times when I layed next to him (in a fetal position) and just held his hand and the tears would just roll down my cheeks. You can't help it, you can only be so strong. I think it's ok to cry. I never bawled in front of him but as I lay next to him, there were times when the tears leaked out.
As his daughter I know all you want to do is lay next to him and hold his hand and just be there and I think that is fine. I'm sure he wants nothing more than to have you there. Just remember that he will be at peace soon and be going to a much better place. You need to cling onto the wonderful memories you have of your dad and you need to do what YOU feel is right. Nobody can tell you what is and isn't right, everyone's situation is different and everyones father/daughter relationship is different.
There isn't a day that goes by that I don't think of my dad. Sometimes I cry and other times I laugh. He will always be with me, in my mind, in my memories and in my heart.
I wish you the best and will keep you and your family in my prayers.