>>280844038 (OP)Kishimoto's writing takes a nosedive after Obito talks to Sasuke about the massacre, which is a common impact Obito has in the story.
But yeah. At least up to his battle with Itachi, his actions make perfect sense from his perspective. Like this
>>280846390 post puts it, the plot is fucking insane from Sasuke's perspective. Specially part 1.