Goinginsane and all you others in the same boat, I'd just like to add my hugs, really.
Goininsane, looking at the first thread that you started before you knew the extent of everything, I got a chill in my spine. I had a very similar situation with my usually incredibly attentive, faithful and loving husband, whereby he started spending loads of time with a woman who he said he felt was "on the same wavelength" as him. She was going through a really tough time and was completely not friendly to me.
We had the most awful time over it and I was never sure if I'd just been really paranoid. This thread is making me wonder...especially as it seems that it wasn't that obvious that so much was going on!
Anyway, wishing you all the best and hoping that you will work through this in whatever way is best for you.