Seems like this is a part 2 of this story. It hardly explains anything. The translations makes it really hard to understand.
So, the reason the emperor treats him so bad is because he loves him, but Du's family were traitors and even though the emperor didn't believe he wasn't one too, he loved him and still wanted him by his side. Then it turned into anger and bitterness and a lot of misunderstandings, because he thought Du loved him too, but now he see's that he only wants power and money and thinks of everyone else but the emperor. Although Du loves him he sees him as two different people. The prince he loved and the evil bad tempered emperor. I'm not sure how this story will continue with what happened in chapter 40. But I'm curious now. I want him to either get kidnapped (so he won't get in trouble) or end up with the blonde guy from the other country.
Emperor's Favor Not Needed