He won't change - you know it and everyone reading here knows it. If he loves you as much as he professes to, then why did he treat you so appallingly .. pretty much right up to the day they put the papers in his hand. And then having received them .... he slags you off to your mother on the phone - telling her you've got no friends, you cut and run, you drink too much, you let the kids run wild ...
You've outwitted him and he's a controller. They hate to be outsmarted ... especially by the one who they (think they) control. You've absolutely blindsided him and right now he knows that anger and being nasty to you is just going to make you more determined to see this through so instead he's going for the broken man, devastated, nothing to live for, emotional, heart tugging, give me one more chance, I'll do anything .... 'character'.
I've been where you are and I caved in. All it did was delay the inevitable.
It was the summer holidays and he'd been even more of a bastard than usual. He went out one evening and as soon as the door shut behind him, I threw some things into a bag, got the kids in the car and did a runner to my parents (hundreds of miles away).
He was never off the fucking phone the whole time I was there, which was the best part of a month. This was 10 years ago so mobiles weren't what they are now - no emails etc and besides he knew if he texted or rang my mobile I could just ignore it. So he rang the house phone. This was before I had admitted anything to anyone and I didn't want upset my parents so hadn't told them what was going on. When he called, my mum or dad would answer all cheerfully, pass to the phone to me .... and I'd have to pretend it was all ok.
The bastard was doing exactly what yours is doing now. I love you, it's always been you, there will never be anyone but you, I don't deserve you, it's all my fault, I've treated you like shit, I'll do anything, if you'll just come home, we can make this work, give me one more chance. He'd ring up half pissed and say I'm going to drive through the night to come and get you. He even got his brother to ring me up begging and pleading on his behalf - 'you should see the state of him, he's lost two stone (yeah right, the fat bastard), he can't eat, he can't sleep, he can't work, he's drinking too much, I'm scared he's going to kill himself ... '
In the end I caved and went home. He was on his knees in the hallway as I walked through the door, tears rolling down his cheeks, kept hugging me every five minutes, swearing on the kids lives he was a changed man. It lasted about three months .... before he was back to his nasty, snidey, controlling bastard ways.
Yours won't be any different and as for that bullshit about packing in his job - that's a threat. Just more emotional blackmail.