I hope you and your partner will be able to turn the corner - and I really believe it can be done.
There is something to be said for getting away from 'all depression, all the time'. This isn't to say that you don't want to address the issues, and of course he will still need help and counseling - it's just that there's also just getting out of the quicksand. Becoming present and being in the 'here and now' - planning for the future and enjoying what's going on right now, even while dealing with some of the stuff from the past.
You were saying something in an earlier post - about being firm - this is a good thing! Keep it up - because this is helpful. Firmly in the present, wanting to fill up life with lots of good things instead of being sucked up into the muck, so to speak.
In the meantime - I really think you should get a red winter coat