As far as dealing with the roller coaster, we've ALL done that part! My very best advice is to stay busy. I was working at the time, so that helped. At home, I cleaned, organized, cooked, like a fool!!! I really did not want to lose my breasts, so I didn't deal with that stress. Have you looked into finding a support group in your area? The American Cancer Society should be able to help you. It's great being able to talk with others about what you're going through. A couple of ladies have had nipples tattooed on and are very pleased with the results. Were you given the option of a lumpectomy? Just curious.
May I ask what type of BC you've been diagnosed with? You said it was caught early - that's a really good thing, meaning it has likely not spread to your lymph nodes. There's no reason to feel guilty. All of this is very stressful.
May I tell you that the majority of women who are diagnosed with BC live a long life and die from something completely unrelated years and years down the road.
Prayers, and HUGS.