Hi Evian,
I feel so sorry for you, I have been there. I dont want my words to seem like a cliche when i say i know how you feel, but i really do feel exactly the same. Believe it or not i have broken up recently too, my birthday is next month, and Christmas is my fav time of year. I have already been aching at this Christmas for a couple of weeks now, because i know how difficult it will be. May be the only differnce between your story and mine, is that my ex and I are giving each other other hard time ALL the time...since the break up.
I won't lie to you and tell you that i am following the advice i am about to give you, but i really believe it can work, ony if you want these days to pass smoothly. A very close friend of mine told me, that i won't be able to do that alone, i have to make use of my family and friends. Really use them, their support, their care. Dont be afraid or shy to ring a friend and even say i dont feel ok, or can i talk to you, or can i pass by and have a chat. Also try to make yourself busy, distract yourself, even with silly things...
I wish you go through this tough time peacefully.....