Hi and a warm welcome to the family and friends group though so sorry to hear about your grandad.
You are far from unusual in struggling after a diagnosis and with my wife's cancer she never wanted a prognosis but often we need to accept the doctors can only make a guess.
You might find it helpful to look at our pages on I'm looking after someone with cancer especially the emotional bits where I am sure you will recognise some of the issues.
<<hugs>>
Steve
