Alec. You are amazing. You're doing really, really well. You sound lovely, your STBEXH is a fool.
You are 'getting there' with regard to STBEXH but you've a way to go.
It's SO HARD to explain how things change. It's almost impossible to make someone believe their STBEXH isn't any different to all of ours. So, so many of us thought they meant what they said rev finances & houses, we thought we could do it amicably, we though, without realising it that 'we' were different. I don't know - closer, more caring about each other, more able to trust each other, whatever, but something that made us able to think 'we' could make decisions between us, that 'we' would both keep the promises we made, that 'we' would be able to be close & friends &.... Whatever.
But, as each hour/day/week/month goes by, things change. His feelings, his guilt levels decrease unbelievably quickly, his feeling of responsibility goes out the door too...yes HIM. Your STBEXH - he will change. But I have no idea how to make you believe that 🙁 I know I didn't.
You're not being 'grabby' to get as much as you possibly can in the settlement. Yes you earn a bit more than him, but YOU will be the one responsible for your children. No matter what he says now, he's walked away and he can walk away from financial responsibility too. Yes. Even your STBEXH. I understand that you're conflicted (and you are, it's coming through loud and clear. You say you don't care, but you do and that's understandable - for now) You will be seething if you don't get the very best deal you can, the very best deal, because whether there us an OW or not (and I'm still prepared to eat my iPad if there isn't) there will be a new partner, he will want to live with her, buy a nice house, maybe even have more children with her. He'll want to take her out, go on holiday, buy nice things for her. By then it'll be too late for you to get any mileage out of being pissed off that he's swanning off doing these things whilst you're finding money for school trips, shoes, hobbies, clothes etc for the kids - plus the mortgage, bills etc to maintain a home for the children. You need to do that now, whist unfortunately you're in a position of least feeling like it.
I know it's a HUGE leap of faith, but please, please, try to hear what we are saying & try to believe he really isn't any different to all the others.l
He's already hidden his feelings from you for a long time.
He's already been totally selfish & not shared them with you - so you could both try to see if you could work together to build your marriage up
He's already seen a solicitor - and bollocks it was 'to see what he needed to do'
He's already acted like a 5 year old and promised the kids something he cannot promise (staying in the house).
HOUSE. Do not sign anything that ties you to staying in that house. Yes, right now you want to, but you don't know what will happen & you need your financial freedom - not to be tied up financially with him. I understand you want to stay there & I understand you thinking it's all the children know & it's their home. But honestly, don't get to hung up on that - it's not always the best thing. Sometimes it's much better to have a clean financial & emotional break. Have a think about how different it might feel to not 'see him' doing X, sitting there, putting his keys there, leaving his shoes there, but actually having a new, fresh home where you don't 'see' him at every turn. It's hard to think about right now I know.
Sorry this is SO long, I wish I could talk to you in person, it's so much easier.
Take care 💐