OP, I've come to your thread late and you've been given some really good advice and support already so I'll try not to repeat it although I would reiterate it. I think this will be a lengthy post, apologies and only take from it anything that might stick 
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My original thread here had to be deleted some time ago - 3 years actually - but I went on to post loads and loads about my own situation. I did divorce my ex husband even though I was going through exactly the same self doubt, self-blame, disbelief, fear and uncertainty as you are. Saffysmum was posting at around the same time in similar circs.
What I see in your thread is a theme which was similar to mine. Your husband is essentially a lazy, self centred and manipulative man whom other people have seen through because they don't have the same relationship with him as you. I bet you're hard working, committed, 'other-focussed' and direct in your dealings with other people and yourself. He is, quite simply, no match for you.
Now - whilst I couldn't make my husband love me in the way I loved him, couldn't change his core beliefs and values about his entitlement, couldn't change his manipulativeness - I could do something about my way of dealing with it. He was 'sorry' and 'fucked-up in the the head' had 'told me so many lies he didn't know which way was up'. OK. Well, he had to do the decent thing and act sorry - not because it suited him but precisely because it didn't.
The first thing I did was I bundled up all the belongings of his that I could (20 years worth) and I just made him come and get them. Whether it suited him or not. I contacted all the utilities, mortgage company, pension provider, everyone and put into motion the process which cut across any possibility of me weakening. Each step gave me a bit more focus on me and my DD and what was best for us. It hurt. But it was right. I swallowed the bits that came out after the discovery and used them to my advantage - for example when I discovered he was living with OW and not 'sofa surfing' I contacted CSA and they sent a big, fat bundle of forms to him. That upset him, but so what? He was LAZY and he needed a kick up the arse. It worked because it made my life a bit easier and who cared how much more difficult it made his? He did because he realised that he didn't have quite so much power to manipulate and self-serve that he'd thought.
So. three years down the line. I know he's sorry. I know he regrets not being honest because ironically he'd have had a much easier ride than he did. I know it in his actions to ME. He hasn't essentially changed by the way. He's still lazy, still self serving, still entitled but it has no effect on ME.
I got me a shit hot lawyer (eventually). She took over and made him demonstrate in action (read financial settlement) his remorse. That's what your husband should do now, but you're going to have to take the reins and lead him to a place he doesn't want to go. It will make you stronger.
As a postscript - DD came home this weekend and she said "Mum, I've always thought that dad's stressyness was all down to him betraying you but I've realised that it wasn't - it's just the way he is". She's right.
Sorry for going on about me - I did so to try and show you that as awful as it is, one day you will look back see that there are very effective ways of dealing with such people once you stop allowing THEM to define YOU.