just looking at it from a different perspective and, dont get me wrong, this is a horrible situation.
Do you want to save the marriage?
Do you want to be with DH?
do you think you have both taken each other for granted and are now stuck in a rut?
If I wanted to save the marriage I would go all out and celebrate our wedding anniversary.
I would book a restaurant and send him a cheeky text at work and make it as normal and romantic as possible. Go to the hairdressers and get a manicure and wear something sexy and try and get the romance back. You need to date him again and remember why you fell in love with him. On the date dont talk about problems or children or work, talk about past holidays or fab meals you have been on together.
If he is stressed at work, maybe he doesnt need to come home to an equally 'stressed with the kids' wife and the normal humdrum of life. I am not excusing what he did or has said but maybe he needs some TLC too and you need to be kind to each other.
Otherwise, this is going down the route of lawyers, divorce, children seeing dad at weekend and I am sure neither of you want that.
OTOH if you dont want him anymore, ignore the anniversary and see a lawyer!!
HTH