I felt totally the same as similar to you I had a 9mm stage 1 but was HER positive and hormone positive too and hence why chemo was suggested. I thought I would need radiotherapy only after my surgery and I can totally relate to your shock. did they explain the reasoning for the chemo? I doubt you would need anything heavy duty for something of your size?
Im on weekly Taxol and using the cold caps to retain my hair . Do talk to your oncologist about the caps, mine was very pro for them, even had pictures on his phone of women who used them and showing me the results . I've had 3 taxols and 3 weeks of caps so within the next week I should get a feel for the effectiveness. Retaining Hair was so important to me hence even though they are uncomfortable I'm happy to tolerate them.
one step at a time , it's hard to take it all in, hopefully the oncologist will explain more and the reasoning etc. totally normal what your feeling.
take care
angie