From experience, get him to the GP and looking for jobs now. It's a whole ton harder to get them out of bed once they've had months, if not years, of being able to put you off with a dramatic meltdown over the very suggestion that they do something because you can't cope, financially or psychologically, with handling everything.
FWIW, going back to work (had no choice because I'd been made redundant, was on the verge of a breakdown and had said I was done), was the best thing DP ever did for himself. The vicious circle of feeling bad about a job, then not having a job, then feeling crap about not walking into another job, so not applying for any jobs, so feeling crap about not having a job, etc, etc, is a lot easier to interrupt before it's got to full circle.
And get him outside. Every single day. No hiding in bed, no staying in there until you get in from work, no avoiding sunlight.
Wake him up when you get up for work. His sleep pattern will be fucked otherwise, which feeds into the sleeping all day, awake at night alone dysfunction. He needs daylight and fresh air - somebody vulnerable to seasonal light levels is likely to avoid daylight, which makes them worse. And multivitamins (to allow for things like low vitamin D or B complex), plus healthy food, will help, too. It's easy to just eat crap or pick at things/avoid nutrients.
And I agree with the others, to become pregnant whilst he's like this would be a huge mistake.