I think sunsetsunrise is right. He needs to have an idea of what you are going through. I'm currently having the same problem with my husband. But here is something that a friend shared with me. Maybe you could share it with him. I hope it helps.
Depression is very motivated. I don't know if there is a more successful
illness in the world. It is a champ, a winner! It sets goals and follows
through with its goals. "I want Julie to be really sick and down on
herself today. I want her to stay in bed, eat junk and cry buckets of
tears." And it sure does do a good job! Depression is serious and
motivated and strong. Without the right tools it is impossible for us to fight it. WE ARE NOT LAZY! WE ARE NOT SLACKERS! WE ARE NOT DUMB, WEAK OR FAILURES! We are sick. Learn our individual signs of depression and help us fight it. If depression is motivated and successful, then we all have to get motivated and successful. If you see us sitting on the couch doing nothing day after day- don't get on our case for being on the couch. Get some tools to help us get off the darn couch! Get motivated, serious and strong, just like depression. Then teach us how to do this. Help us find the right mix of medications, alternative treatments and lifestyle changes that make depression the failure instead of making us look like failures. We need your help to fight this illness. We need your love to beat depression.

Tell him it's not his fault. He just needs to be patientwith you, and to show you he supports you and that he should not blame himself for the depression. Tell him that it will help you to here we will get through this together.