Hi. I feel for you, in fact I was in your shoes once. I had Stage 0 Breast Cancer. It was very early and very very small, but the word "cancer" freaks anyone out. I was only 43, had never been sick in my life, never smoked, was of normal weight, exercised...etc. and had only gone for a routine mammo.
I have learned a lot since then, such as there is a very high survivor rate with certain types of cancer. You don't know for sure if your nodes are involved. If they are, they will remove them. The treatments are much better now, I hear (they didn't have me go through chemo though). My friend had breast cancer two years ago and she really wasn't half as sick as I expected her to be, going through the treatments, and is full of energy now.
Please keep your great attitude, and PM me if you have surgery questions. If I can't answer personally (I chose a masectomy because I'm a nervous ninny--I didn't need one), I can put you in touch with my friend who chose a lumpectomy, had radiation and chemo. She is the sweetest person you could ever meet. Keep us updated.