OP my DH was diagnosed a month before we started palliative treatment and that was nowhere near Christmas.
I absolutely understand how you feel but all I'd say is try not to look at it as you versus the medical bods. It won't help. They won't be trying to withhold treatment from your DM, and they won't be trying to upset you. It really isn't their fault your lovely DM has such awful cancer.
Go for the GPs appointment first thing tomorrow morning and do not be fobbed of by reception. You need an emergency appointment to get the ball rolling. The GP will refer to Macmillan and in addition, most GPs are pretty hot on palliative care - in my area, the hospice nurses refer everything back to the GP anyway, so all scripts etc are from the surgery.
There is a whole new level of service available for terminally ill patients which fortunately most people never have to find out about .
While you're with the GP, ask about a 'just in case' box. We didn't get told about it until it was too late really and it is useful to have for in the middle of the night emergences.
My DH died earlier this year - do PM me if you have questions you want to ask off board.