What can I say to fix it that isn't just mean and spiteful?
None of the above is mean or spiteful.. It's just the facts of how you and any spouse deserve to be treated.
If they can't treat you nicely, then they don't get to be near you.
If you put a child with someone who is mean to that child, you tell the child to "stop playing with them" right?
So, he has to play nice, or you are taking your ball and going home...
And right now if he's not going to a FT to own his marriage its time to take your ball and go home.
You aren't being mean to take your ball and go home if he is being hurtful or isn't cooperating... So, don't argue, don't yell, don't fight.. Just state that if he can't treat you with the respect a wife deserves then you are exiting.. and do so...
Don't even give him a chance to fix it this first time... He will try to talk you into turning around and staying.. just keep walking...