How will I cope without my dad in this world?

We found out yesterday that my dad has stage 4 pancreatic cancer that is also in his liver.  He has been told that both an operation and chemo are not an option.  I have not stopped crying since hearing the news.  We knew this was a possibility but having it confirmed is beyond awful.  My dad is the best dad anyone could ever have, both my brother and I have been so lucky.  He is 89 and my mum had just started to plan for his 90th next year.  We all live in different parts of the UK but we would have given him a great party.  How will I live without him?  I'm 56 and have a great husband but I still call my dad to ask about practical household things as he always knows what to do.  I can't imagine what he must be thinking now when he goes to bed and my heart is broken just thinking about how scared he must be - even though he won't admit it.  I don't know how I'm going to cope and can't imagine what my mum is going through.  Life is just so awful.  I want time to stop.