You certainly deserve your moniker of cancerchamp. Dealing with her2 cancer seems like enough of a mountain to climb without a second cancer and long term side effects. I hope you have family and friends helping you through all of this. Since I am still a newbie here, I am not the best at navigating this myself. Since my heart is breaking for you right now, I am going to attemp to answer your question about other treatments. You already had chemo, and some of these treatments are approved for 2nd or 3rd treatments after taxane, and or hercepton. There is one that is only available under specific guidelines and I am not altogether sure what those are. But Genentech has a website for her2, they make Kadcyla. they also list two more drugs on this website. It looks like you can use this to help guide questions for your doctor.
https://www.herconnection.com/
Do you have someone to go with you to appointments? Have you asked your doctor about other options?