Need Advice: How to Support DH

I’m worried that my husband is on the cusp of depression. I know the inertia of that is so hard to overcome, so I want to do what I can to help prevent that, if possible. He is feeling very low and frustrated because he has been passed over for promotion the last two years and because of this, and the need for more flexible work-life balance as a parent, is essentially being fired from his firm, probably in January. He has known this was likely for a few months now and has been trying to apply for jobs, request informational interviews, and do online tutorials to try and support a career pivot but it hasn’t yet yielded any offers. I think these things take time and want to see him land in the right job with strong growth potential - which I tell him all the time - but he has never been unemployed before and is just feeling all the pressure to have something lined up ASAP and disheartened that he doesn’t. How can I help him and try and keep him from slipping into a full blown depression? He is a great father to our 13 month old and we are just starting ttc #2. I need him in fighting shape so he can get out there and be confident and find that great job.