We are hard to live with, for sure, but apparantly your husband feels you're worth the extra effort. Depression kind of distorts your point of view towards the negative, so if he doesn't have a problem with depression, maybe his opinion of you is more realistic right now than your own? Please try not to drag yourself down farther feeling guilty about ruining his life, it may not be the life he expected, but you don't know what the future holds, or what he sees when he looks at you. It could well be a lot more positive than what you see in yourself. You could be what makes his life worth living, despite whatever problems you have.
You know, there are days when I can't even ask for help, let alone offer any. There are posts that I just can't relate to in any way. There are some where I can relate, but can't think of anything to say. Every so often though, someone says something that I have lived through and come out of in one piece with a little help to give someone else. There are so many different people, with so many different experiences on this forum that even where I'm no help to someone, there is sure to be someone who is, and the same applies to you. It isn't all one sided to accept support when you don't have much to give, because it also helps the person who is helping you, and as you grow you will have more to contribute. Hang in there, ok?