My prayers and thoughts are with you, Master Buddha and your family. I know how hard it is to lose one's father, mine passed in 2012 from that horrible disease. Speaking from my own experiences with it, I hope you know that you probably were there when he needed you most, that he knew you were (sorry, but I'm not sure how it was, my father had 2 other rare diseases that went on during his Cancer bout, too, which we don't know if he knew what was going on or not).
Also know, that you're not alone, our thoughts, our prayers, and my sympathy is with you all. Hold together, and remember that he is forever with you, as long as the memories remain. *hugs if allowed*