Dear @rladdley
I am sure it may not feel like the happiest of Christmas tides but at least surgery is out of the way and no node involvement, excellent!
I had a mastectomy and axillary clearance - several nodes looked dodgy but only one was malignant. As that node was HER2 ( the main tumour wasn’t), the recommended course was chemo, herceptin and then I had Letrozole thereafter (hormonal therapy). My chemo was over six months and probably heavier than your intended regime, because of the node involvement. As far as I know, I had no side effects from herceptin at all. Eight years ago, it was administered by infusion, but now by injection, so quicker and much less hassle. From my experience, therefore, go with the herceptin! It’s been a proven asset for some time. If Letrozole is planned later on, side effects can vary. I have a couple, possibly compounded by my age, but very manageable and no aches or discomfort. Take these steps as they come, you don’t have to buy an entire package in one go. Best wishes.