I'm very sorry, Missadventure and Storynana, to hear of the losses you've suffered. Regardless of age, it is very hard to lose a parent. Both of mine died many years ago but I still miss them and always will. There is also no denying that the first Xmas is particularly hard.
All I can say is - be kind to yourselves. Don't be afraid to accept help when it's offered. Do whatever makes you feel better, whether it's getting as much rest as you can or keeping yourself continually busy. Indulge in anything that cheers you up a bit (I've always found that a nip of something alcoholic helps!) And tell yourself that this will pass...the loss will always hurt but, eventually, it won't be so raw.