Contact and avoiding backsliding

After receiving text messages from my ex declaring his love, obviously stating how badly he feels, asking for my forgiveness, blah blah.  I spent the evening in a state of anxiety, irritation, had dreams/nightmares, that focused on him, my fears, the usual. 
I read more information, reinforced and rationalised that this is a disorder I'm dealing with, read back through the abusive messages he'd sent, remembered the patterns of abuse, compared his minimal effort to re engage to what my efforts would be if I had actual remorse over my bad behaviour, what would I say, how would I be self reflective, to what extent would I want to have resolution or understanding, how worried would I be about the other person?  Obviously his response came up predictably short, and I was forced into the sad and empty space that forced me to realise that I've been attracting and turning cartwheels for a reflection, nothing real or of substance. (sad and depressed) 
Today I received emails from him, the same, 'I love you, you don't know what this is doing to me, I can't function or exist, please speak with me'  Against my better judgment I wrote back. I simply explained with as much detachment as I could that, 'I find it very hard to be convinced that anyone who feels love for someone can treat them with such cruelty', and that, 'I wouldn't even imagine speaking or acting so dreadfully towards an acquaintance, let alone someone I claim to love'.  I wrote this not realising that I was still stupidly expecting that he might actually 'get it', that he may feel empathy (face palm) When will I get it through my head? 
His response was, 'Ok, I give in, you will not hear from or see me again, but remember I love you and always have, yours always .......xx'   I guess he's supplying the reinforcement for me that he is not and has never been equipped to deal with any intimacy, or emotional sophistication that regular folk need to do in order to maintain relationships, even without the toxic garbage that he's generated into our experience. I now feel depleted again, I'm eating for comfort for the first time in my life. 
I of course know that this will not be his last contact, he's done this before, and he will contact me either when he's drunk, or when he feels crisis, he has a court case coming up, I'm guessing he may contact me even while he's drunk to ask for help in his time of crisis. That will be a big test for me. 
I'm also very aware that as I get my head around the obvious absence of emotional attachment we shared, that any perceived emotional connection was just me imagining and projecting, I'm realising that I'm craving sexual connection with him. I feel like I want to have sex with him because I miss it, and am not having sex with anyone now, and because I have a perverse idea that I want to try and have sex with him and keep my head around the fact that it's just sex, nothing more, see how it changes the experience, and if it will shed light on any of my illusions of what our 'false intimacy' actually was. 
Mind screw.