My Dad has just been diagnosed with stomach cancer

I’m sorry to hear about your dad’s diagnosis. It’s hard to get your head around and so many emotions. Both my mother and father in law have passed in the last year, and I continually said to my husband..you can’t have this time again, so go with your gut instinct! 
So do whatever is right for you and for your dad! Show them how much you love them and how grateful for all they did for you! If you want to write a letter, go ahead! 
The little things mean so much.. watching a TV programme together or just sharing a cup of tea!

Hopefully there will be a treatment and you will have many days and weeks to show him all the love you feel! 

Thank you for your kind words it's really appreciated