Jareth - it probably is all related to a stressful job, but I agree with a previous poster that he shouldn't carry it in and pile it on your shoulders.
My dh hated the forces towards the end and it was a nightly process of grumpy, depression etc.
I have had depression for most of the last decade but I self manage it in the way that you described. He however feels that he should cut a huge slice of his depression and land it onto my plate. I found he was making me worse!
I didn't contemplate leaving him, I remember the good times and that is what got me through it.
I just got tough - and dismissive, embarrassing to say but just like I treated my ds when he was learning behaviour.
If he starts on about work - I'd say, right is this a problem I can actually help you with, no, then I can't really see how I can help.
If he did the put downs or gestures I would just get up and say " right, when you want to act like an adult and admit you have been a prick, I'll be In the bedroom/kitchen/ conservatory waiting for an apology."
I stuck to it, too, sometimes I didn't get the apology but I got better behaviour. He didn't get my attention and time of day when he was behaving ( and it was only behaviour I have to add, not a personality disorder) like a respectful adult.
Sad to have to treat him like a child, but he was acting like one.
Lots of people have stressful jobs, tell himvto find a way of dealing with it - a game of squash, a bath, half an hour to himself, and then he has to come back to planet bloody normal.