Sorry I haven't read all your thread and I would like to before I pass comment. I just wanted you to know I am also in the UK and in the very early stages of similar situation to you (I am the W and my H is in love with another W) and we have two children. He is still living in the house but openly carrying on the A.
As I said it was just to let you know that I am in the UK so on the same time frame I know it can be frustrating here when you want some support but it's the middle of the night in the US.
The only thing I would say is I've been here before 15 years ago that ended in D but it was my choosing in the end and the support I received on this website is what I have to thank for getting me to that point.
Once I've read your thread perhaps we can catch up some more.
SJ
Me 46 H 39 M 11 T 14 S 10 DO 8 ILYBNILWY 11.06.17 Separate rooms 11.06.17 ILW OW A ongoing 12.06.17 Kicked H out 23.6.17 H came home 20.8.17