He's simply torn CW. It seems to me that he want's things to be the way he wants them to be, but he's scared that they will go back to the way they were. He doesn't want to risk that, but he still loves you and is attracted to you. That's pretty obvious.
You're on the right track, but you have to be patient. I wouldn't verbally discuss this stuff with him too much because it brings back the bad memories. Notice that's exactly what he went to when you brought up the R talk. Don't ask him so many questions, eventhough you really are dying to know the answers.
You can have that sexual conversation, and ML without it being associated with the guilt by not asking him so many pressuring questions, etc. That's causing him to act on his emotions and then feel remorse afterwards. Hence the getting up and heading out immediately after ML.
Try it next time. Find a way to get the same result, without the R talk, the questions, etc... and maybe he won't feel the pressure and will stick around afterwards.
FLoyd The grass is always GREENER over the septic tank.