I Hate Him...Why Am I With Him??!!

Our relationship has deteriorated so much with time...and I know that all relationships change...but it seems like this is more than that. He derives glee from tricking me, making me feel small and stupid, he likes being the quick and smart one. I come out in a an outfit for our night out and he tells me about the President's approval rating...I am not by nature disposed to men, so my patience with their quirks is relatively little...he knows this...he has pushed well past it. He is not physically appealing to me, has not been for a long time, his personality is quickly losing it's luster, the only thing left is the commitment of our children and the time we have invested in eachother...
I don't want to be cold...I don't want to be cruel...I am by nature a very emotional person and I do love him in my own way. He is a very hard person to love sometimes
though. He is abrasive, sarcastic, harsh, cold, self-absorbed, distant...he can also be loving and warm...and cuddly. However, he is more one than the other as you can see, though you'd never get him to admit it. Still, you might say I must love him a good bit or we wouldn't have been together for almost 12 years...but you must rememember that I was raised by a domineering psychotic bitch. I have a natural tendency to gravitate to dominant personalities. Although I do love him, in my own fashion. I also hate him now for the same reasons.
So what do I do?? When the House of Cards, so ill constructed,crumbles and there is no Fairy Godmother, what happens?? How does the fairy tale, or the nightmare, end??
I haven't been able to get hold of my therapist since Christmas, so I'm turning to a different outlet for answers...
NOW WHAT??