I only saw this thread today and have read all your messages. I don't normally post, but I wanted to tell you I'm another stranger, who with all the PPs here are thinking about you.
Believe me when I say your messages do show an improvement week on week even if you don't see it.
You are grieving what you've lost, which is perfectly natural. Any grieving process has bad days and not quite so bad days.
You will never get back what you had, or thought you had, but you will move on to something else. Because life always moves forwards, never back. We can't change what's happened, what's been said or done, but we can change how we think about it.
You can challenge the thoughts that keep popping back into your head; the things you remember. Acknowledge that they happened and think if you can think about it in a different way.
For example, when you remember how he spoke about her children, a more helpful thought is that they're his problem now.
When you ask yourself how he could treat your children like this, a more helpful thought is that you might never find out, but your children are lucky you would never do that.
When you think you don't know what is left of your life, a more helpful thought is that you may not know now, but you will be able to fill it with things you want to do and there is every chance you might meet someone else in the future.
Have you thought about counselling? You may be grieving too much to consider it right now, but if you have to wait for the NHS it might be good to get that referral as soon as you can.
Grieving takes up so much mind space, but think about what things do you like doing. What did you use to do and enjoy before you had children? What are you good at? If crafts are not your thing, what is?
Finding something you like doing for yourself, not just chores, might help.
I heard in a webinar that doodling is meditative, as while drawing something you think only about where your pen is going next.
I'm sure many hobbies are the same. I can completely loose many hours when I'm sewing. It doesn't have to be a full on hobby, just something you like and that you can do in the evenings when your mind is likely to wander. And if it doesn't stop you thinking, add binge watching something at the same time.
As PPs have said before, preparing your next steps, looking at finances etc. Is also a good way to keep occupied.
It's about reclaiming your life.
I know you're not thinking about these things right now, and rightly so, but you will get there at some point.
I know that you don't want to burden your children by talking to them about this, but if you did you might find that it might be what you all need. They're grieving what they've lost too.
We're here if you need to vent.