Her2+3 no lymph nodes

I have stage 2a breast cancer. 3 tumors in the left breast. All 3 were Her2+3. One was ER+1, another was ER marginally positive and the 3rd was ER neg. All were PR neg. Lymph nodes neg. I went through 4 cycles of chemo after a mastectomy. Now my dr wants me to take Femara. When I asked why he said because of the her2 positive. It makes the cancer more aggressive. I was told they got all the cancer, it wasn't in my lymph nodes and my chances were 80% in 10 years. Yet everything I read about Her2 says that it is more likly to come back and may not respond to chemo. I'd love to hear from others that are Her2 positive without lymphnode involvement.