It's going to be a bumpy ride

[Dom R]

he said "No, no. I need to hear this sort of thing."

sounds like he's still wanting you to be his concience and "talk him out of it".

I am having a hell of a time acting "as if". I am scared out of my mind.

I dont think this is the time for "acting as if". I think this is the time for standing firm and letting him know what kind of boundaries you have, and then STICKING TO THEM!!

remember: he has been asking you to set moral standards, the whole time. he's been asking you to basically yell at him and get a backbone, for months now.
He will not respect you, if you dont show that you have moral standards, and stick to them.

What are your moral standards? how many times did you go out, before you had sex, for example?
I think your approach to sex with him should be consistent with what he thinks your moral standards are, to some point. If it was a long time until you had sex... i think you would be very justified.. and almost EXPECTED by him.. to have no sex whatsoever while he is living separately.
If on the other hand, you jumped in the sack relatively quickly(by your own choice)... it kinda gets blurry. unless what he's been implying, is that he wants you to show more moral firmness than you have been previously.

That's my guess on things, anyway. good luck,and supportive prayers for you.