Wow Emma,
I really identified with your post. I had a high grade tumour, lumpectomy, chemo and radiation. That is not why I identified with your post. I related because I also feel guilty about complaining. I am so lucky to be alive! I am so lucky I still have my boobs! I am so lucky I didn't have a really bad reaction to chemo! Etc etc....
I too have tried to be cheerful and grateful but every now and then, I need to have a bit of a meltdown and cry and morn the loss of my hair, morn the loss of my figure (I put on 20kg) and just be sad for everything I have been through and what the future might hold. 98% of the time I am upbeat but occasionally I really need to be sad and shed a few tears. I feel guilty but I need this and you do too!
When I first visited my surgeon, days after discovering I had cancer, I told her to take them both off! She performed a lumpectomy and double reduction (apparently F cups weren't desirable for radiation). At the end of the day, I have some scars but they are still my breasts and my nipples and I am so grateful that she talked me out of it. I can't imagine what you must feel to have some foreign lumps on your chest. You deserve to morn the loss of your breasts and there should be standard counselling for this.
I am rambling now but basically I am saying that you have every right to feel whatever emotions you feel. Give yourself the chance to feel, to be sad, to morn your loss. We are all taking this journey with you. Thank you for sharing.