Help?!?!! i destroyed my boyfriend's self esteem? (didnt mean to)?

ok so my boyfriend has nvr had very high self esteem. He's promised to try and be more confident for me but last night while we were talking I said that he was too sensitive AGAIN. kinda said that he was a jerk sometimes too. And this made him feel horrible bout himself. I tried to explain that I only brought up that he's sensitive because it causes us to argue constantly. ( we've been arguing a lot lately) he then claims that I don't love him the way he is cus I said he was too sensitive. I do love him for him and like I said I only brought it up cause it causes problems for us so I mention it to try and fix things between us. Anyways he says he feels like a piece of crap and that even his gf doesn't accept him ( I do and love him very much. We've been together for almost six months now. Don't know if that helps but I'm also his first gf) he always says that he doesn't deserve me and that I'm too good and all tht non sense. Would it make him feel better if I tell him tht he's too good for me? What can I do?? Oh and also he's tried telling me that I can do better and that I shud dump him for someone else. I need help to change his mind about himself! Please don't say anything affensive or tell me to dump him cus I'm definitely not gonna do that. Is there anything I can do to boost his self esteem? ( btw he saids tht I was the only thing that he was tryna be confident for and I destroyed that by saying he's too sensitive). how can I get him to accept himself? I have also tried to tell him everybody has flaws but he says he has too many which I disagree with. Thanks for reading this whole page of writing. advice anyone??