I'm so very sorry for your loss fam. I remember reading about your dad and my heart goes out to you and your family. Please know that NT is here for you. Happy to PM you if that's easier but my NT family helped me and we can help you too. As
@Methodical Management said don't look at it like your dad lost his fight to illness but know that he lived the best life he could and he would be very proud of the lives that you've touched on this message board. I lost mom a little over a year ago and the grief is real. Take your time to grieve is all that I can tell you. There is absolutely no way to take a short cut through grief. It takes time and don't let anyone tell you any different. The first days and months were hardest for me and I found myself crying most of the time. Crying was actually very therapeutic for me. I still have days where I miss mom but when I think about it I didn't want her living like she was just to he here for me.