In the past we've gone through cycles where he does well for a week, and then he'll forget for a day or two, and then he'll just stop trying. My struggle has been not letting my hurt and pain get in the way of me meeting his needs.
Disclaimer for anyone reading along:
I know both Created and her husband in real life so I'll be saying things based on stuff that someone just reading the OP would not necessarily know. Just didn't want someone to think "where did that come from?" when reading my response.
Now on to my answer:
Knowing what I know about your husband and about you, I suspect that a part of him giving up trying is because he doesn't feel that the things he can do are good enough. NOT because you expect too much, but because he wants to do so much better and so much more. Even during the times you've been over at our house when things have been a little "off" between you, even I, mister can't read people to save his life, can see that in his mind and heart you are a princess who deserves all the best. I honestly believe from watching you two interact, that one of the greatest sources of disappointment in his life at the moment is that he can't do for you all he wants to. And if he can't do it right, he gives up and does nothing. Again, it's not about you being unreasonable in what you expect, it's about him wanting to be able to do so much more.
In terms of what to do about it, make a big deal about the things he does do. If he gets a noticeable positive reaction from things that he may feel aren't good enough, he'll probably be more inclined to continue them.