Whether or not he has an OW is irrelevant, really.
He has hurt your feelings in a cruel selfish way. Then he says HE needs space to think about things. I guess it is YOUR job to become "fanciable" again? 
o.k., I am trying to imagine my DH saying this to me , and acting like this. My reaction would be anger. Anger at him dropping a bomb like that without regards for my feelings. Anger for him refusing to do anything to improve the matter, anger for telling me all the times we made love he did not fancy me and it was all a lie, anger about him making it all about HIM.
I would give him space. I would give him lots of space. in fact I would ask him to leave for a while so I could get my thoughts in order.
Then I would, like mad, figure out a future without him. Check finances, lawyers etc.
Wait for him to contact me, if he doesn't, I'd move on to divorce.
I would go out as much as I could bear with friends and family. i'd go on fucking holiday without him.
I would try to be very cool and aloof.
If he would come back and be upset and say it was all a big mistake, I am sure I would forgive him, and we could could work it out TOGETHER.
Waiting and hoping he will change his mind as long as you play nice, and give in to all his demands for space, and try to be nice and reasonable...yeah, that suits him maybe. But maybe not. because he will start losing respect for you (even more).
The more of an appeasing victim you are, walking on egg shells, the less he will respect and love you.
I think it is essential to be tough in this sort of situation and find your inner tiger, your inner strength. And then thinks will work out. You deserve better. You have to believe that. You deserve respect and love from him. or else, he doesn't deserve you.