I think your H getting nasty and mean after your dinner together shows -
1.He's scared 2.He's angry, most likely at himself as well as you for the M woes.
Just try your best to stay calm and not react to the emotions he is throwing at you. After all when we are not calm and are mean and nasty, its much easier for the spouse to feel justified leaving us. Do DB and 180.
I know its hard not to react and it's hard not to try to figure out why H is doing what he is doing. We have to learn how to detach, we must focus on ourselves.
My H has said a few things lately that without DB, I would have become angry and yelled at him for saying. I no longer react in a negative way to anything H says. It takes steel will sometimes, but I feel better for doing it. When I find myself feeling weakened, I excuse myself and go to a quiet place and re-group. Positive self talk helps. I tell myself I can do it, no matter what it is.