My mum used to (well still does, I just don't see it) get stressed to the hilt every Christmas. Repeatedly reeling off lists out loud, ordering people around, shouting at people for not having done an pointless things she'd deemed essential for Christmas but hadn't asked ordered them to do. (Like scrubbing and polishing out kitchen cabinets.)
Christmas morning was painful, getting into a tizzy going on about what she had to do (Christmas wouldn't been Christmas without her running to and fro louding and repeatedly saying "the bird, the bird" (until my grandma got it sorted and into the oven).
First Christmas my DH and I did for several people I genuinely thought I must have forgotten something major or must be doing something wrong.
Yes, there's generally more to do than for the average day, but no need to get manic. Just get on with it.
It'll still happen without five different crackers and eight choices of cheddar, or having your hair blow dried.
Mind you, if you're married to a lazy oink or have someonewho is critical of things not being to a high standard (without making it happen themselves) I can understand it isn't easy.
I only enjoyed Christmas on the 26th as a child, when we didn't have to reach a target of perceived idealism.