Unravel my head please

[Minervaowl]

I have lived in a largely sexless marriage for over a decade. We had children via fertility treatment but my husband has always had a much lower sex drive. He also has a lot of issues from his past that make him very controlling and defensive around money - our finances run entirely separately, he has money I don't have access to for example.
After years of my begging for counselling, which he resolutely refused, I had a one night stand. I was appalled with myself and told him. I also said I believed our marriage was over and that I wanted a divorce. I'd already seen a solicitor, which he knew about, but like everything else, he just ignores things he doesn't want to hear.
He was furious about my infidelity but then calmed down a few days later, and said he recognised how far I must have been pushed to behave that way, and begged for us to stay together. For me, the damage is done, I'm so over being rejected and controlled by him. But he's booked psychotherapy and counselling, and been to the docs re sexual problems and some other health issues I'd nagged for years about.
I'm adamant I want us to separate as I simply cannot imagine him/us ever getting to a place where we have anything approaching a normal sex life, even if we fixed everything else. He is devastated and swings between desperate tears and promising me anything I want.

I don't want to hurt him, or rip him off or anything. He's an adoring father, and has no other family beyond us. He said the only way he will leave is if I "make him some promises" along the lines of eventually him moving back, not seeing anyone else etc. I've told him I can't promise him anything.

What do I do?

Update:

I've started seeing a psychotherapist, I've only seen her once so far but I'm v impressed. What becomes clearer and clearer is that there really is no fixing this to any satisfactory degree.
My husband is trying very hard to "save the marriage" and has upped his game no end, but then gets pissed and shouts at me.
He says that he's talked to my parents and that my other says that what I'm doing (talking about divorce, spending less time with him wtc) is mental and domestic abuse.
He is absolutely refusing to engage in any discussion about splitting up, and says that under no circumstances will he be leaving the home, or allowing me to take the children and if I want us to split I have to leave alone. I've pointed out that that essentially forces me to come in hard with the lawyers and I really didn't want to do that.
I suspect he's going to argue that he should get custody and I'm an unfit mother or something. He's been signed off work with stress and for the last week has done the school run and now thinks he's dad of the bloody century, and that I'm shit.

What do I do? This is hideous.

Ugh. He is horrid. The only thing that will make you feel better is taking some control of the situation - which in practice means seeing a solicitor and taking things further from there.

What's your relationship with your mother usually? I really wouldn't believe him on this (or anything else).

OP ask yourself this one question - do I want to spend the rest of my life with him? Forget about the house, the children, the family, the friends and everything else.

The talking to your parents would be the nail in the coffin for me.

I hope I am not being too simplistic. There are obviously lots of things to consider but imo women, including me, always try to see a situation from everyone else's point of view first. Do you want to spend the rest of your life with him?

What Goats said is it really. You need urgent legal advice with a view to putting things into action asap. Apologies if I missed it, but how old are the DC? I think you're right to suspect what his plan is likely to be. Being off sick with stress is unlikely to be a winner with regards to residence/making you out to be unfit - but he'll no doubt give it a go anyway.

Hang onto your hat, Minervaowl. You can regain sanity later. Right now I think what you need is a whole load of furious determination. There's totally no going back to the option of saving anything, even friendship, after that kind of exchange I'd have thought. He's declared himself to be an adversary.

Tipsy the children are all under 5.
I've suggested that we have counselling together - from my point of view, it'd help him HEAR me when I say I don't see a future for us and start to get his head around it.

However now he's saying he will only go if it's with a view to moving forward and fixing our marriage and unless I do that, our relationship will be nothing except nasty. I said we needed to have better communication for the sake of the children but he says he doesn't want that, and we had better fix it.

I had it out with my mother and begged her to not offer counsel. She had told him that under no circumstances should he move out of the house as separations don't work. I pointed out that all she's done is put me in a position where I'll have to fight him legally, whereas we might have had a chance at something more amicable.

Browers, do I want to spend the rest of my life with him, once the children are out of the equation? No. No. No.

Your mum is really not helping! I hear you loud and clear about staying with him. For what it is worth I left my XH 17 years ago with a 2 year old and one on the way. I won't say it was easy but it was better than being with him.

Throughout all the tough times since I still believe leaving him was the best thing I ever did for myself and the DC. Take care of yourself.

Agree with Cabrinha, tell him what he wants to hear to get the ball rolling.

He is saying that if you disagree with him he will stay and be nasty. If you agree with him, he will stay and be "nice."

Get copies of his paperwork, and get thee to a Shit Hot Lawyer.

I'm not convinced this man has any ability to even be pretend-nice. And that's the thing, pretence is a lie. Everything he says to you now is probably a lie. Everything he does will be nasty and loaded with bad intent to break you now. I think the situation is quite dangerous. Please do as TheSilveryPussycat advises.

I'm too annoyed at your mother's actions to even contemplate a response to her despicable behaviour, which has most certainly thrown in a huge grenade to an already twisted environment.

Just my opinion but you'd be well out of your depth to even consider staying. Would you talk with Women's Aid? Practical advice and support might be helpful now.