TCHP chemo stopped working?

Hi all. I was diagnosed with HER2 positive (ER8/PR8) in February 26. Tumour 25mm. Started 6 cycles of TCHP in April. After cycle 2 my tumour had shrunk to 15mm. Had an ultrasound after cycle 4 and it hasn’t shrunk further at all which was incredibly disappointing to hear. Breast surgeon said the remainder could be scar tissue but he didn’t sound very convincing. I asked him if any point in going ahead with the last two cycles. He said that is a decision for my oncologist and its the ‘standard protocol’ to do so. He has requested a contrast mammogram to help inform that decision. Any of you been in this position? The way I feel at the moment I’d rather go straight to surgery. I have experienced delays with every cycle due to neutropenia (hospitalised once) and just feel so mentally and physically tired now .