Experienced racism for the first time today...

So I am from Brazil, but I have been living in the US for 6 years. I was at this furniture store with my kid and we were speaking Portuguese. I was ready to purchase something and I asked one of the sales lady for help and she told me to wait (I have no accent when I speak English, so she understood me just fine). We were waiting to be helped and another sales lady that was not busy gave us a condescending look, and made a very rude comment about us to the other sales lady (she was not aware that I heard).

After that I didn't say anything and just left. I have never experienced racism directed at me, and honestly I dont know how to feel. Idk if maybe I'm just thinking its racism and it wasn't. I am starting to doubt what I heard. Idk if I am angry, sad, ashamed of my culture, or if I'm just over thinking it...

I don't even know why I am sharing this, maybe I need some advice on how to handle this situation, idk...