Delurking to tell you that things will be better - I 100% promise you that.
Apologies for the long post, but you reminded me so much of me (apart from the church going and cooking) during my split that I wanted to give you a nudge to keep going, you'll get there.
I made the decision to split with my ex in Aug 2018 - we'd been together for about 22 years and there was a bit of an age gap. Over time, he became controlling (I could only go to work and back alone and god forbid I didn't answer my mobile). If he did come along to days/nights out, he was grumpy and so tight with cash I used to ask if we were doing Krypton Factor if we were expected to equally sure two sandwich, packs, three cans of pop and four packets of crisps between five of us for lunch. Back then our household income would've been about 85k - yet we never had a holiday abroad as he hated flying, we went camping most of the time and drove shifty second hand cars which broke down constantly- but it was ok for him as he had a work van. I did all the childcare arrangements and school related stuff, despite working ft and earning more than him. And one day I just had enough. Enough of him constantly moaning about the kids and the state of their bedrooms, moaning about them maki g a noise, moaning about absolutely everything. Gave him three chances to change and he didn't. We went to financial mediation to sort those out as I was doing the divorce online - as he refused to pay for any of it. Mediation was an eye opener and surprisingly even the mediator clearly thought he was a prick by the second session.
Soooo anyway, asked him to leave in Sept 18 (as he couldn't afford to buy me out, but I could him). He didn't start looking at rentals until early Dec and finally moved out on 4th Jan. the period in between was awful, he wouldn't leave the house, wouldn't contribute in any way to the runnjng of the house, wouldn't shop or feed the kids (at that point he was on sick leave, 100% pay whilst I was still working). He refused to let me sleep alone in the marital bed, so I ended up in my youngest's bed - which wasn't great. He'd get drunk every night and tell me exactly what he thought of me. Luckily my best friend lives two mins drive away and I spent a lot of time there, mainly getting drunk and walking home when I thought he'd be asleep. She also talked me out of stopping the whole divorce process more than once when it got too much.
He left on 4th jan 2019, had the kids twice a week at most in his new two bed rental (despite having three kids and being able to afford bigger). I knew from the start I'd end up having them full time - but I wanted it to be his decision so the kids would've blame me later if you know what I mean, but I wish I'd just put my foot down sooner - like from March 2019 - when he was awful to them. Like you, I have one child who has mental health/ emotional issues which are ongoing and it's very probably he was a large contributor. However he decided in Sept 2019 that he couldn't cope with the kids and their behaviour and didn't want them to stay with him anymore but he didn't want to give me any more money - surprise. He then moved 250 miles away with someone he'd met five months previously who hates the kids and has gone on to sick pay - meaning I get no maintenance now.
But, I really couldn't give less of a rat's ass. The kids dislike him immensely (his own fault) and hardly see him. They are so much more full of life and far more open and chatty than when he was here and will hang out downstairs rather than lurking in their rooms. I don't mind if they want to slob about during the weekend as long as the basic chores they have are completed. We're in Covid times, what else is there to do? Schoolwork has Improved and we (I think) all have a good relationship.
I got some counselling about 6 months after he left and found that helped me hugely (and I'm the least likely person to have expected that). I also started to prioritise me for the first time ever - bought a spa (had always wanted one), bought a new car, got a tattoo - basically lived like a teenager with an adults wage for a bit. Almost savoured the freedoms I'd never had when I was with him during my late teens through to 39.
I'm now divorced and it's brilliant. Do what I want, when I want, how I want and only have to take the kids into consideration. If you don't pay my costs you don't get a say (and that includes my mother 😂). Our Financial Consent Order is still ongoing as he refuses to pay for legal advice - doesn't bother me as I'm paying him and the agreed amount has been in my bank account for almost two years now. Maybe he'll get hit by a bus and I won't need to pay out!?
I know you're in the worst part of the process, the last few weeks and days. I had a countdown on my phone and my best mate would text me every morning without fail to say "14 days to go" etc, which let know someone else also couldn't wait for him to fuck off and leave us all alone. On the evening of his departure, I had a leaving party for him. He wasn't invited, but my friends and I had a great time. And that's another thing I've noticed, pre lockdown, my house was a lot busier after he left. Friends popping in for coffee, coming round for drinks or dinner or off the cuff. Wouldn't have happened with him there as he was a dark cloud in the corner, waiting for someone to entertain him and pull him into the conversation. I don't miss it at all.
This time next month, you'll be in your new place, you'll be free of second guessing someone else's mood waiting for them to swear or stomp or be huffy. You and the children can eat beans on toast for a week, if that's what you want, because you don't have to cater for "meat and two veg man". And every horrible moment that you've put up with to get there will be absolutely worth it. You've got the Mumsnet massive behind you too - we know you can do it