There are some kinds of injustice that are not one’s fault such as racism, classism, and sexism. I do not know what source has already answered this question, but I think when one feels that an injustice has occurred to one’s self, one needs to figure out what happened, what caused the injustice, and what makes it to feel like an injustice. It is important because when one is to speak up, one should be sure that what occurred was actually an injustice, and it’s not just a dent made to one’s own ego. I believe that before one resists/fights injustice, one should consider why it happened. If it is an injustice, one should speak up against it because if one doesn’t speak up, it will never change.
This site down below gives ideas how to fight for injustice.
So you are questioning the level of injustice? It is different for everyone, true, so how can we make this question more clear?
There must be a movie or story out there that addresses this question. Keep looking.