My husband went through really bad depression last year. I found, like you, that just being more loving and attentive made it worse. What helped in our case was combining that same love with the message “You are too important for me to let you behave this way.”
I don’t know if your husband has this reaction, but my husband perceived my loving attention and lack of criticism as being patronizing - saying he wasn’t important enough for me to ask more of him. He knew he was letting me down, and facing that was too hard, so he just kept withdrawing further. Although he was clearly stressed by high(er) expectations, letting him know that I really needed him and his behavior mattered to and affected the whole family really seemed to be what he needed to hear. I tried to keep the message positive, but couldn’t hide how hurt and stressed I was. It seemed to come through anyways.
I also found I needed to repeat myself about what our family needed from him - especially me. I really needed him to show me some emotional support, especially by letting me know that my job mattered. I asked him to please ask how my day went, over and over, until it finally sunk in for him how much this mattered and that he really could influence my health and mood. Once he started to believe that what he did mattered, things got better.
My husband also benefitted from me talking to him directly about the possibility of clinical depression. He was starting to really believe that he was lazy and uncaring by nature, and the possibility that he might actually have a fairly common treatable condition really helped him cope with those negative thoughts about himself. He was able to say, “I’m not a lazy person. I’m just depressed right now.” I suspect that this might vary from person to person, but it helped my husband.
This is the best website I’ve found for family and depressed persons. It has great information about different types of depression and ways you and your husband can help him deal with his depression / depressed behavior. It does deal more with clinical depression and depressive disorders, while your husband may just be “down in the dumps”, but maybe there will be some useful information there for your family.
HTH, I know how hard it is to have a depressed spouse when you really need them to be strong. If you find something that seems to work, please post it. I’m still looking for more and better answers. We’re coping, but we’ve learned that my DH has a milder depressive condition called dysthymia that remained after he recovered from his more severe depression, and that still affects our daily lives.