Mama2005,

I am so sorry that you feel this way, I think your family will understand and if they see your changes at least they wont be talking amongst themselves about how you don't look sick.
We all know how we hate those words. I know that sentence about doesn't sound very good, but I come from a very large family and I know that is how they would think. Some of my brothers even like to tease me a little about it, but I know that it is all in fun and they really are not bothered one way or the other on how I look. They all care for and love you.

My thoughts for you are very simple.....and I really think you should go.
You said that you keep them updated via email, so the next email just let them know about the nose and the other things and take a picture, like Jolanta said, and send it to them in the email and tell them that this is the new you and you are looking forward to seeing them at Christmas time. (fore warn them, so to speak).
I think you will be fine and will have a wonderful time. If not, pop on over to Australia and we will show you a good time (and you can smack me for telling you to go).

Best of luck with your decision