Oh dear. I posted here on earlier on the thread, and things have moved on, but haven't also. The reality is that you are talking to the ether, where every single poster has a different experience of life and love. You will not receive the 'answer' you're looking for, until you stumble across a poster who reaffirms wherever you are subconciously.
The real answer is, there is no black and white. Some people have been where you are. Some people have wanted to be where you are. Some people have thought about where you are but put all their efforts into staying where they are. Some people have never been where you are and think you are the devil incarnate.
Once again, I'd reiterate, I was where you were in the 'stuck'period, of feeling lonely and sad, but ended up on the other side in terms of DH being the one to finally look outside the relationship, so I hope I have a wee bit of overview on both sides, many years on.
You won't find an answer here, and you'll find vitriol and support in equal measure, as in real life.
In only hope that you'll find the strength to realise that this is about you understanding whether your relationship is over or not, without the OM or the cries to get to it and sort your DH with a blow job that will make it all OK.
Relationships break down. You don't have to sacrifice yourself for your children, as to do so would also affect your children. However, you owe it to yourself, your children, and the future, to give yourself some space to analyse this without ethernet posters - maybe get some non-relate counselling about where you're at, and how you've got there.
We would pull a man to pieces if the poster was the other way round, but only cos this is called MUMSnet!!