The speaker keeps asking one question, almost like a plea: why do you act like I don't have feelings? The repetition shows how hurt and tired they are. They aren't shouting. They simply state the obvious, that they have feelings and are human too, and can't understand why someone refuses to see it.
In the second stanza, the speaker argues that it's natural to feel something even when the thing isn't "factual." That seems to be a reply to being told their emotions aren't justified or don't make sense. The speaker insists that feelings don't need proof to be real.
The last stanza turns the question around. The speaker asks for a reason and says the other person must prove they are human, since someone without feelings would hardly seem to be. The mood is raw and vulnerable, with a quiet edge of frustration. The short, plain lines make it feel like a direct, honest conversation.