I feel helpless

He always points out my flaws. He says he's just making observations, not trying to criticize me or insult me, and that it shouldn't upset me, but I can't help but get upset. He says that I'm too sensitive. He says he's an a$$ and he knows it, but that he shouldn't have to change who he is because that's his personality. I just want him to be nicer to me. If I'm upset, I try to talk to him calmly and openly, but he gets so defensive and it turns into an argument. If I get emotional at all, he gets mad at me and completely ignores me. He says he doesn't want to encourage me to be upset about something I shouldn't be upset about, and it makes me feel like a child being sent to my room. I need advice.