If you have the time, energy, and desire to send out Christmas cards - congratulations!! That's something I gave up years ago (way before the bomb.......). I spend time and share greetings with those that are important to me. Those that I care to know about my "sitch" know (but then for me it's been quite a bit longer than most).
For me, it is so hard to deal with the holidays - the emotions and all the good memories that now seem tarnished by what has transpired - working on starting new traditions and focusing on what I still have - that spending time on Christmas cards truly seems like something I don't want to spend my time on. Christmas greetings should not stir up any kind of stress or bitterness. IMOO (just an opinion) , if you can't send a Christmas (CHRISTMAS) card without putting something negative (in any way) in it, I wouldn't do it. AND don't stress about it - focus on you and your family!
"Do not look back in anger or forward in fear, but around in awareness." - James Thurber