My personal experience:
When i realized and truly understood and believed that whatever i do with my life has no direct impact on others life, including my beloved ones, i got completely free of those negative feelings about not being a good person. I've realized my definition of a good person is based on what i think other people are thinking about me. But like what you wrote couple of days ago about "you can't change anyone", we can't control or change the way people think about us. Everyone has their own definition of good or bad based on their own approach to the life.
If i hold a negative feeling towards you because you didn't reply to my comment i'm gonna give away my authenticity to you (other people in general) and suffer from it every time it happens to me, unless i learn my lesson that i'm not dependent on others behavior towards me. Then you've helped me to get free from it. As Matt Kahn says everything is here to help you. If i reply to your post or comment from a point of obligation then i'm your emotional prisoner and subconsciously i'll hold a negative feeling towards you, even if i'm not consciously aware of it. That feeling usually turns into hate and stops us from loving ourselves and others. In my understanding it's not being a good person.
So as you said about priority of self love, no matter what circumstances or situations are, love yourself so much that it overflows and pours towards others.