This is a normal response to a devastating diagnosis. The 19th December wasn't long ago. It's okay to cry. It's okay to feel scared, angry and sad...all those things. It's completely normal. I would be more worried if you had slspped on the happy smile and just got on with life without a second thought.
Use this time to think of the necessary things you might need to do. You will move through this phase eventually and carry on with your new normal life. If sadness and tears are overwhelming in weeks to come then it would be a good idea to talk with your supporting/treating team and/or seek some counselling. Kath x