How are you holding up binders? Today must have been exhausting!
Hopefully you're at your sisters right now, taking a much needed break with a glass (or a few) of wine and lots of chocolate 
Despite my own personal experience, sadwidow's recent comments make total sense to me. In fact, they remind me of something wise my father made me consider during the early days of separation from ExH.
He asked both ExH and I to talk with him, individually, with a view to helping us reach the right conclusion for DCs in the most impartial way he could. ExH went first, which I later realised was for DF to ascertain whether ExH was truly remorseful for his infidelity (which it seemed, he was).
When I talked with DF, he asked me a very important question, and told me that no matter what my answer was, so long as I was truthful, he would support me moving forwards and offer the best advice possible.
He asked me whether I thought I thought my future would be happier without (ex)DH. To cut out all the cp about whether or not I could forgive him, how much it had hurt, whether the DCs would be better off with a two-parent family, and everything else... Because, as he pointed out, as he thought (ex)DH was truly remorseful, in time all of those things could be resolved. Whether I could see myself being happier without him in the months and years to come was the most important question.
You have no need whatsoever to answer that question on here binders, but you do need to answer for yourself.
In my case, I knew both then and now that I was going to be happier on my own. I have no regrets with the decision I made, and several years down the line I can say with honesty that things are MUCH improved between us, and we both do what is best for our DCs now, despite all the hurt and resentment from those dark times which followed.
From what I've read so far, I'm inclined to think that you would prefer to separate. In which case, my advice is this: hope for the best, but be FULLY prepared for the worst.