What do you think of people of colour?

I was born in Australia, I have an Australian accent. Yet I still feel super insecure about not being Caucasian. Whenever I go to the shops I feel like some old white people look at me with disgust. And I’m sick of them commenting on social media. Every time I see a POCs comment section there’s always comments like “Go back to your country”, or “You’re not Australian”. Like where am I supposed to go back to? My question is, is this all in my head? What do you think of people of colour? and should I be upset about this?