”I think for some it's an extension of the general Christmas related stress and anxiety. There is so much going on, pressure, living up to peoples expectations, family silent feuds. I wonder if the faff of dinner and the facc that's it's the highlight of the day itself means it's often just the straw that breaks the camels back, as it were.”
@tellmewhenthespaceshiplands - I agree with this. I know that I am prone to stressing over things, and the cumulative stress of organising the presents, the cards, the decoration, the food etc does get to me. It has got better over the years, as I have worked out the short cuts and tips that make it easier (shopping online, making things in advance and freezing them, and buying a Christmas pudding instead of spending 6 hours boiling Delia’s pudding, just for everyone to be too full), and so I am much less likely to make a big deal out of it than I used to be, bit I can still be pushed over the edge if something goes wrong.
The dses still tease me about the Great Goose Leftovers meltdown that happened a few years ago. I had a plan for the food over Christmas that had roast goose on Christmas Day, cold gammon (cooked and glazed on Christmas Eve) with baked potatoes and coleslaw on Boxing Day, and the leftover goose cooked in honey, five spice and soy sauce until sticky, and served with rice, on the 27th. But when I went to get the leftover goose on the 27th, half of it was missing! Ds2 had decided to treat himself to a delicious roast goose sandwich for his lunch.
It really wasn’t a disaster - we had salad, some leftover goose and cold gammon, and no one was going to starve, but it was the final straw for me, and I completely lost the plot - there were tears, there was shouting, there was snot and more tears - and dh had to take me away and give me a stiff gin to calm me down, then sort out supper. 
It Is a family legend now - I will never be allowed to forget it!