JimJams - how are you feeling now?
I understand what you are saying about the fight, and was thinking about you yesterday, and how advice might just as easily wear you down.
It is possible that however much you chivvy and fight, you might well be stuck with no help. Not right, not fair and not just, but reality nonetheless.
What is there within you that enables you to be the 'coper' that you are? Is there any chance of developing a routine that enables you to have an hour to yourself before your DH leaves for work - to read, do yoga, on-line gambling or whatever?
Can you find ways to 'stagger' the holidays and maybe find money for one week's paid help as a liferaft to look forward to in the middle?
Keep a dairy or chronicle each evening, including the best and worst of each day, with polaroid pics?
Allow yourself a MN moan once a day at a given time so that everyone can listen, and heap insults on people who make it harder than it should be?
Take to drink and ask your DH to bring you nice treats home every day?
Anything to get through each day as it comes.