Hi LilRedWG, just saw this thread and wanted to post.
I am so sorry for your news, how awful. I thought I'd share my experience with you - my dearest Dad was diagnosed with stage 4 'mixed' lung cancer in Oct. Mixed means both small cell and non small cell types are present, and is a real prob for treatment as the 2 are treated with different chemos but you can't do both at the same time. It means that if you treat one, the other grows and vice versa so after about 6 wks of chemo they gave up. he is now on radio and that is making him suffer (much more than the chemo did actually).
That said there are some good things: after the initial shock, which is horrendous and is what you are prob now feeling, I felt almost grateful to be given warning that I would lose him. That is the only blessing of cancer, at least you can prepare. Since then I have made him happy by telling him I am pregnant (weirdly my pg is dated from the exact day he was diagnosed - the 1st day of my last period was that day). I have seen him much more than usual - around every two weeks (they live 2 hours away) and we have tried hard to build great memories, so lots of meals out, family outings etc. he adores seeing DD and she really cheers him up because toddlers don't understand long-term sadness (ie. that which is not caused by removing a toy from them!) so we all have to forget our sadness when she is around.
He doesn't want to talk about death or really much at all about cancer, aside from a bit about treatments and stuff. That sounds similar to your dad. I find I am able to respect that he wants to live his last weeks/months having as 'normal' a life as possible so we almost ignore it. I think he would hate it if I insisted on tearfully telling him how much I love him every time I see him so instead we drink a glass of wine or have a nice meal and talk about Barack Obama or taking DD to Longleat or what to buy in Tesco tomorrow - really ordinary stuff.
I absolutely adore my dad and will miss him so incredibly much. It will be terribly sad when he has gone but I try not to be too sad now (while also trying not to repress my feelings - a tricky balance!) since the bonus of right now is that he is still here.
I am thankful for that.
And right now he is able to live a decent life. He is a bit weak, has a bad cough and is breathless and a bit wheezy. His hair has gone grey and some has fallen out but he didnt have much to begin with! But he gets up and brings my mum tea in bed most mornings and can drive here to see me and can go out for meals and have a perfectly decent conversation and reads the paper every day and is generally quite a lot like himself, while not being 100% of course.
I don't know if any of this rings any bells for your situation, which of course is very unique. I just thought it could possibly help for you to know you are not alone. I am so sorry for you. It is possible to actually enjoy these last weeks with your beloved parent, once the initial shock wears off.