If he is not sleeping during the day, it is probably best to encourage him to at least do a couple things. Lying restless in bed often makes it even more difficult to get any sleep. Maybe gently prod him to take a shower, change & lay on the couch (or at least just get out of bed & lay on the couch). If there's something you would normally do together (watch TV, eat a meal, read, do puzzles) get that set up for the both of you & tell him you're going to start if he'd like to join you. Start doing it yourself; he just might jump in for a while. Try not to worry if he tires quickly. It's pretty good progress if he at least tried something.
Most sleeping pills should start to work within a day or so. If they haven't helped yet, talk to his doctor. It is way too hard to fight depression if you are sleep deprived. Paranoia can be a direct result of not sleeping. I know for me it always is. Get that under control first & then you can deal with the depression itself.
The counselor & doctor are both great ideas! That way you have partners in helping to get him well. It is so hard to feel encouraged by anything people say when you are really depressed. People would tell me to snap out of it & I would get mad and tell them they didn't understand anything. Others would tell me that it must be so difficult to be so depressed & I would get mad and say they were being patronizing. What felt the best to me, though perhaps it would be different for your husband, was when people would just treat me like normal (even though sometimes I would scream "why won't these people just leave me alone?!"). They would invite me to do things & be okay if I didn't want to go out. They would tell me about their own day & ask about mine. They didn't judge me any more or less than normal. I really can't say why that helped. It just felt so horrible to have people completely change their behavior just because I changed mine. I try to always remember that in my good times and treat others the same when they face times of deep depression.
It sounds like you are being really supportive of him. Even if he can't express it right now, I'm sure there's a part of him that appreciates all your efforts. Once he gets a week or so of sleep, if things are still too unmanageable, perhaps you could talk to his psychiatrist about a Day Program (usually 3-4 hours of intensive outpatient group therapy each day, M-Th/F). There are always lots of options. Hang in there!