Hello there, I'm sorry this is showing up in your life but glad you are being presented options.
I don't know any of the traits of your cancer, but it sounds like your doctors think that lumpectomy would be fine.

My cancer was on my right side at about 7 o'clock, IDC, grade 2/stage 1, 18mm in size, ER+ and PR- and HER2- (it's the PR- that makes mine a little more sinister)

I was presented with the same option and chose lumpectomy and radiation. Both went easily and healed well (no node involvement, good margins). I know that radiation side effects take a long time to fully manifest, so I am doing things like long gentle daily chest stretches and ongoing moisturizing protocols to help it along. Going well. I have full feeling everywhere and scar lines are modest. I had a mild rash area about as big as my palm that just itched, easily handled by various creams. When I look at myself in the mirror now I can't tell there was anything done, except slightly more dimpled skin in a few spots.

My reasoning was personal (as yours is too): In my case, I couldn't handle that much destruction of tissue, even if it would allow me to skip radiation. My body hasn't been cut into a lot, and it's traumatizing to me on a deep level. Your situation might be different based on the traits of your cancer and your feelings on the subject.

I'm still pondering the aromatase inhibitor topic. That's a tough one for me, for quality of life reasons.

Not sure if any of this helps but I am sending you my best wishes!