You are such a great writer Val. You put everything I think into words.
I am not in your shoes yet, I have not lost my parents yet, but I do share your sentiment. People at work are like happy holidays and I say that's nice, people close to me lose their loved ones, this is a horrible time for them, but yeah, happy holidays. Some people look at me strange, others understand.
And I have responded a few times about the "stress" of not getting all presents bought, not having enough time with holiday cards, with things like "yeah, I heard chemo is a good time to do holiday cards, but thankfully you are here instead of there" or "be thankful you have people to buy for", etc, etc.
There was some incident at work and the office manager wanted to know who told me something and I wouldn't squeal. We argued and I literally yelled at her (which is something I do NOT normally do) "You know, I really don't care, is this cancer related? is this life or death? is this medical related? No, then I don't care, not worth my time". I can't imagine having said that 3 years ago.