I need help supporting my very depressed husband

My husband and I have been together for a long time. He's a great man with so many wonderful things going for him. But he doesn't see any of it. He thinks he's stupid, boring, ugly, fat, and a burden on everyone around him. None of that is true, even in the slightest bit. But when I tell him that, he says I'm wrong and that I'll realize it sooner or later.

He keeps bringing up divorce. I know it isn't what he wants. He says it's for my own good. He doesn't want me to be unhappy and he thinks he's dragging me down. He thinks he's a burden. I tell him it's not what I want. He says I'm wrong, and I should leave him. That he's doing me a favor. No matter how much I try to convince him how untrue that is, he won't believe it. I told him that I meant it when I said for better or for worse. But he says he's "not worth it" and there are other men who would be a better husband and could actually make me happy. I told him that even though I don't think it's his job to make me happy, he does make me happy. It's when he talks about divorce that I become unhappy and upset. But that just gives him more reason to believe he's bad for me. ("See? I do make you unhappy. Just leave me.") It's like this circular reasoning type thing. There's no using logic with him. Which I understand. Depression is not a logical thing.

Another issue is he doesn't think he wants to get better. He "wants to be this way." He won't get help. He hates therapy/counseling. Doesn't want to take medication because he's afraid it will "make him different." (Don't even get me started on that one. I know just how wrong that statement is.)

He gets in these "moods" that are becoming more and more frequent. I still get moments of him where I see the happy man I married, but it seems like I get less and less of him these days. He absolutely hates himself which is so hard to see. He's not suicidal, but sometimes he says things like the world would be better off if he died/never was born.

I've struggled with depression myself, and have been on antidepressants since I was a teen. I was suicidal myself and I pushed everyone in my life away. So I understand a lot of what he is feeling/saying. I know none of it is true, but it is still taking a toll on me. How can I support him while keeping my own sanity? He's absolutely worth the pain to me. He doesn't think he is, but he is. He's truly the best man in the world and even though he's going through a tough time, I know I'm the luckiest woman in the world to be with him. We are both in our 30s if that helps. No kids yet. Hopefully eventually though.

Please help us. How do you reason with a person who refuses to use logic and reason? Any good phrases that might resonate with him? He is highly intelligent which is one of the reasons I think he's so hard on himself.