3x Positive Mucinous Cancer (HER2+), anyone with experience?

Hello! I was recently diagnosed with Triple positive Mucinous Carcinoma in my left breast and I have an appointment set up in about 11 days. They did a fine needle biopsy and IHC to diagnose me. I've been reading that 3x positive mucinous cancer is pretty rare because most Mucinous cancer of the breast is HER2-. I am seeking people who were in a similar position. I'd like to hear about your experiences and what treatment was like for you. Thank you so much.