How do we know that he actually felt this way at all?
…That’s a serious question, not a rhetorical one.
It’s documented, I believe through personal letters, that he was one of the more conflicted Confederate figures. But this has been expanded/exploited by Confederate apologists to the point where people say the conflict proved he was actually honorable in spite of his actions (which is a commonplace stretch of the evidence), and then so were the other Confederates (which is the point where you need to start booking a room at Ye Loco Klansman Hotel)