Well done Dolly, I agree that you're an awesome lady.
I also agree with the wise poster upthread who says that he'll ramp things up in one of two ways next: he'll have a 'breakdown'. As a MH nurse, I've witnessed my fair share of breakdowns, and as a regular mumsnetter, and an ex-Mrs Twunt, I've unfortunately seen a fair share of 'twuntdowns' too. He will possibly try (and think he has) turn all this around, and it will be your fault. My twunt's mantra, after screwing around, and treating his family like shit on his shoe, was 'she threw me out of the family home' and regularly bemoaned same to anyone who would listen. When this had no effect whatsoever, because twunts live in their own little parallel universe created to make themselves teflon coated, and the rest of the world saw through it all, he then went into phase two, 'I had to leave her, I'd have had a breakdown if I stayed' routine. Again, no joy with this, so predictably enough, we quickly moved onto 'I'm having a breakdown because no one cares about me (except OW who is rapidly losing her appeal) and that's not fair' scenario. Lots of feeling sorry for himself, lots of veiled threats 'I can't cope' shit and lots of emotional blackmail. If your twunt does this, then ignore, ignore, ignore. His shit, created by him, for him to deal with. You need to detach and stay strong, and not get involved. You didn't cause the affair, and you won't cause the aftermath.
Alternative to this (or following it) will be the 'going to stall on the divorce and fight dirty, just because I can' phase. My twunt was a master at this. He ignored all the solicitors letters, he buggered off to Greece and didn't turn up to court, he really did the twunt equivalent of throwing all his toys out of his little pram. It cost him far more financially than it needed to, and pissed lady twunt off no end, because she thought he was stalling because he wanted to come back. The solution to this is get yourself a shit hot lawyer, and let them deal with it all. Don't get too embroiled in all the delaying tactics, because that's what he wants. I told myself (after he'd ignored yet another deadline) that in my heart I divorced the twunt the day I chucked him out, and the piece of paper making it official would be great, but it didn't really matter if I got that a month of two later than I hoped.
Your parting shot was great: I borrowed my much missed grandma's: "I wouldn't have you back if your arse was stuffed with gold." That worked too.
I've waffled, sorry, but in a nutshell, get the divorce rolling asap.
Saffysmum x