I'm so sorry that you've been bombed all over again, Kissak. I am glad, though, that you can now see clearly why he has been treating you so unacceptably poorly. I agree, all the anger, restlessness and "what are you thinkings" are manifestations of his own guilt.
I'd suggest that when you confront him, have your friend there to keep things from getting out of hand--your H seems to be very angry at the moment. Also, as you fear, he will try to make YOU look bad. The best way to avoid this is to stick to one statement, and keep repeating it as often as necessary. (Perhaps, "Please leave this house as I can no longer tolerate being in a relationship with an adulterer.")
If you argue with him, or defend yourself, or yell at him, or tell him what proof you've got, or engage with him in any other way, then he can rationalize that you are being angry or unreasonable or misinformed, or whatever he wants. Just like all the other times when he had you doubting yourself, he will twist the truth. By sticking to a single statement, you turn the focus back on him, and you remain strong and don't get waylaid from your primary truth: he needs to leave.
As the others have suggested, don't say anything to him until you feel strong enough to do it calmly, and you have organized anything you need to do before hand. And you're right not to try to contact the other women: if they're damaged enough to fall for him in his state, they can blind themselves to anything they don't want to see/hear.
