I’m triple positive too. I had mastectomy because my tumor size was very large that lumpectomy impossible. I also had the exact treatment as your Oncologist told you. The type of chemo I received (I believe you will get the same from your description) was very mild. I returned to work the day after my chemo and never experienced chemo brain. Fatigue did not start until the last month of chemo. I walked a lot, even on the day of chemo, it might helped. The only thing bothered me a lot was rashes on hands. I had to cook for myself so with both hands full of rashes, it was very uncomfortable. I wish you best of luck and God bless you!