The great thing with her2 is there has been great breakthroughs with treatment which means her2+ cancers aren't difficult to treat as they were some 20 years ago. Unfortunately Google doesn't seem to highlight this fact so it all looks very scary when diagnosed.
I'm 2.5 years cancer free since my regime ended. My niece is 16 years cancer free (she had 10 positive nodes and was Her2+) . My bc was estrogen+ and her2+. (Stage 1 grade 3). Know there are many survivors here thanks to the current available treatment and there is also clinical trials ongoing for improving outcomes for women who develop metastatic disease.