I agree with the others, don't beat yourself up over it. This is an extremely difficult time for you. Your emotions are running high and the holidays are difficult.
You need to take care of yourself first and foremost. If that means not dealing with your family right now then that's ok. Let them know that you appreciate their love and support, and what you need right now is (to listen, some space, whatever you need them to do).
Also, if you feel like the anxiety is getting the better of you, make an appointment with your doctor to discuss getting some meds to help you out. Many people here do, it's nothing to be ashamed of. I got a mild anti-depressant which I ultimately decided not to take (would have interefered with my nightly glass or two of wine!) and also something to help me sleep which I did use until I got back on track.
If you love somebody, set them free. http://tinyurl.com/2empx2g