I have supported 3 friends through divorce.
One found her husband had a 2nd wife and 3 children in his country of birth. He would go there often, on the pretense of seeing his mother. My friend wouldn't as she didn't like the country so she stayed in the UK and looked after their 2 children. Her ex even sent the money my friend thought he was putting aside to get on the housing ladder in the UK to his other wife.
There have been warning signs. I tried pointing those out to my friend as diplomatically as I could. She is a professional woman. Her ex was very clever and got away with his double life a for a very long time. When my friend found out she filed for divorce. When she turfed him out of the house he turned really nasty. My friend is now getting treatment for PTSD.
My other friend (another professional woman) had a controlling husband who never helped with house work and was in and out of jobs whilst she worked like a work-horse. Her father passed away suddently from a heart attack. A few weeks later my friend decided life was too short to put up with this nonsense. She filed for divorce and has no regrets.
My 3rd friend (a solicitor) thought she found her dream man many years after divorce when her own son grew up. Admittedly, the man was earning a fraction of the money she was earning. My friend worked hard to maintain the standard of living she was used to whilst subsidising him in the process. Then her mother became unwell and required lots of her attention over a period of many months. In that time frame, her charming man found a lovely lady a few doors away to befriend. This new lady was on low income and her house was in disrepair. My friend's now ex couldn't make up his mind up so carried a secret affair for about 3-4 months. He eventually moved out. My friend tried very hard to lure him back (for the reasons best known to herself, love is blind, I suppose). He was adamant he wanted to stay put. He has stayed with his new partner for almost 2 years now.
A close colleague of mine found out her husband was having an affair when their baby was 6 months old. She kicked him out on her mother's advice. My colleague regretted it very much not taking her ex back when he came begging 6 months later.
Four women, 4 different stories. I re-read all your posts. I can tell you are grieving the life you had. You are living hell on Earth.
The advice I am going to give is very much based on my Buddhist practice. I do appreciate you might have been brought up in a different tradition or have no interest in religion at all. In this case, please disregard what's not applicable or disregard altogether.
I believe you could do with a compassion, courage and wisdom of a Buddha.
Compassion towards yourself to start with. Based on my experience, women often blame themeselves for the break-up. "If only I was a better wife". This is not strictly speaking true. No one is perfect.
Compassion towards your ex. He might have genuinely believed there was no point in talking to you and moving out was the only way to preserve what's was left of his mental health. We don't know and we don't have a way of knowing what sometimes goes through people's heads.
Courage. Courage to imagine the future where you could be happy with or without your husband. Courage to look at your past mistakes with unflinching eye and resolve to never do it again. Courage to carry on for the sake of the children.
Wisdom. Wisdom to take the correct action. In Nichiren Buddhism we arrive at this wisdom by chanting Nam-Myoho-Renge-Kyo and studying Buddhist guidance. I have posted a link to a Buddhist book yesterday if you wanted to have a look.
I am really worried about you. I have been through a lot of difficulties myself and I have supported a few of my friends. So I have an appreciation of how you feel.
Please call Samaritans 116 123 if you feel you are at a breaking point. They also have chat box on their website if you are worried the children might overhear the converstion.
I hope it helps.