Hello js (for short!).  Christmas is a terrible time for the recently bereaved and indeed anyone who is spending their first Christmas after losing a loved one.  The rest of the world seems to be having a great time (although that of course is not always the case for a variety of reasons) and those who aren't feel shut out from everything going on around them.  I am sorry you are feeling so low but - from my own knowledge - it is better once the festive season is over.  The cold January weather seems more in keeping with your feelings. 

Everyone grieves in their own way and in their own time.  Unless it continues to a point where it is seriously impairing your health and the things you need to do, it is quite normal to feel the way you do.  I would say that bursting into tears regularly over the Christmas/New Year season is well within normal parameters.   I am so sorry for your loss.