I couldn't agree more with Irfan.
Your dad is still with you now Stephen, and although I can only imagine how hard this is for you and your family, you still have some time left with your dad. Spend as much time as you can together and say everything you need to say.
On another note, I know that I only know the half of it, but the effort you have made since finding out about your dad's condition is huge and I am sure he recognises and appreciates this. Keep your chin up and even though the zed is going, us members hope we will catch up with you at some of the meets or for a pint this soon. Chin up!