@Partyintheusa2012
In your other post about your suspicions you were really calm about it all.
I am sorry it all came out this way - no matter how much one is ready for something, knowing for sure still hurts.
For starters - take care of yourself. You will be OK. You have a solid financial position and that helps if you decide to separate.
Also - do not feel the need to do anything or act Immediately. It takes time to figure out what you actually want.
In your other posts you said that you actually wouldn't have minded if your H asked for an open marriage. So - clearly there is something going on in your marriage that isn’t working for you two.
He acted on it unilaterally - and it is, of course a shock.
(As an aside - People don’t easily ask for an open marriage, assumption being that women would never agree to it)
It’s up to you what you do from now on. You sound like a person who makes decisions rationally.
So - you could choose to see if you can re-build your marriage with some sort of new boundaries for both of you - once the initial hurt subsides - obviously.
Whatever isn’t working in your relationship can’t be ignored anymore and counselling is the first step in trying to address it.
Or - you could choose to move on and go back to the UK with your kids. Rebuild your life. Hopefully in a controlled manner - so they aren’t affected by sudden move, etc. I’d at least let them finish the school year. Use the time till then to negotiate financial agreement with your H for going forward.
It’s natural to want to know and ask questions in the immediate aftermath. It’s a coping mechanism. It’s how we make sense of what has happened.
It does’t matter what you ask. You don’t need a list. Just ask what you’ll want to know.
Some people break up in this situation. Many people don’t. Have a look at Ester Perell’s webcasts - her years of experience as a couples’ counsellor i think give her a unique perspective on it all