luvless, I think you are being gaslighted; being set up for the big finish. You say he is getting a big promotion? And he's so full of himself right now?
The times when he's being "nice" are just part of the process, kind of like you're his "good-for-now girl." Exhibit A: the office party. He needed his nice, respectable wife to stand at his side.
I think you should be gone more often when he gets home, breeze in and out of the house at odd hours, go to the movies, bookstore, whatever. Just stop being available to him anymore.
My heart aches for you, but I know that you can pull yourself together enough to do some big 180's.
