nlt, I agree with new attitude. You need to get your mind off H (I know it's so difficult to do). Try and find a new hobby, get to a gym, things that will help you not think about him as much.
OW sounds like a manipulator. H is so mesmerized by her that even if they disagreed, she probably gave him an explanation that sucked him right back in. That's how many OW work. It may be a very long time before H realizes what she's really like.
Me47 H46 S13 M16 Piecing since May/09
"Life is 10% what happens to us and 90% how we react to it." Lou Holtz