My dad is terminal and I feel lost and confused

Hi, 

My dad is the most amazing, positive, happy and loving person in my life and I can't imagine what life will be like without him here. I have a big family but me and my dad are like two peas in a pod, we can sit in silence all afternoon and I feel so peaceful and content with him even if we don't fill the hours with conversation. 

He's always been an amazing grandad to my brother and sisters children and for years I couldn't wait until I could finally have a child so they could have him as a grandad too. After 3 difficult years that my parents supported me and my husband through my daughter was born. Her and my dad have an amazing relationship and his face lights up when he see's her. He makes her laugh more than anyone and crawls on the floor to play with her despite being seriously ill. I'm terrified that she will grow up and not remember what an amazing man her grandad is. I'll always tell her but I want her to remember and I'm devastated that the chance may have been taken away from her because of cancer. 

We were told in Feb that my dads kidney cancer had returned, it's now spread to his lungs, pelvis and lymph nodes. He's had radiotherapy and is on injections to strengthen his bones and attends regular scans to monitor the growth. We know he's terminal but they can't say how long he will be with us. I can see he's in pain but he tries not to show it, he has other health issues and it's hard to see his body give up when he has such determination to live. Why didn't doctors pick up the cancer earlier when something could have been done

At first my dad was certain he wouldn't die, that something would happen and he'd be cured. Recently he's said things that have made me realise that he's started to accept his fate. I don't feel ready to lose him, and can't imagine him not being here to hug me when I'm sad, make me smile or play with my daughter.

I feel such a mix of emotions and I'm not sure what to do with them or how to let them out. With my daughter being so young I look forward to her first Christmas, birthday, holiday ect but then it hits me that my dad may not be here to share in these moments. I feel like I'm grieving already when he's still here then feel so guilty. 

I'm sorry for the long post, I just had to get some of my confusing thoughts out.