I think that if you could sell the truck for a small loss it would be worth it, to avoid one problem in your M. However, the depreciation in new car values is one reason I don’t buy new (I’d be happy to buy yours for half of its new sticker price). The financial hit is too large IMO. Couple that with his demand for you to pay part of his bills and you can really be set back, just at a time when there is enough financial uncertainty in your family’s life.
I still think the truck issue can be worked out. Getting rid of it is the easy answer if you’ve got the money. A counselor is the other approach since I don’t think the truck is the real issue. What will it take to get the two of you back into counseling ASAP and at a higher frequency, say at least once a week (just for a month or so)?
Have you suggested he read any books? He really needs to learn about anger and verbal abuse. There are plenty of books on that. Did you buy a copy of Schnarch for him? Your communication seems to be grinding to a halt and you both are retrenching to your defenses. This trend is dangerous and you must do all you can to reverse it. You need to find ways to talk. The answers he gives you are NOT important. Expect him to say “No” to everything. Just keep talking. He needs to vent (as do you), so that will take some time. Only then will some of those “No” responses change to “Maybe.”
In my situation, after each such talk, my W and I were usually on better terms (at least for a while) since we both felt heard. But there were plenty of times when we ended with a fight. The one thing that comforted me was when she would begin speaking to me in a civil tone with in a relatively short period of time. Little by little that cooling down period shortened. That was a very comforting thing for me, even though I knew issues were still up in the air. It meant that she was not automatically running to the divorce camp and in her way was actually pushing herself. So a first step may be to try and shorten this turnaround time. Just try to get to the next conversation. Forget about what is actually said. Just focus on how often you two communicate.
About his drinking. I am confused on exactly where this stands. You say you hate his drinking and how he acts. But then you said he doesn’t drink that much, only a six pack over two weeks. If he drinks it all at one or two sittings, then I can see some problems, but if its only one beer at a time, I can’t see how it would “transform” him. I suspect the angry behavior you dislike is there regardless of whether he drinks or not. So I am not convinced he is an alcoholic yet (though he could be quickly making himself into one).