Nicola, I don't know the details of your situation, but here are some thoughts from me, the busybody, anyway,lol.
We all are on this board trying to save our marriages, but the thing you don't realize until you begin to reconcile, is that the old marriage is gone. My H and I might as well have gone through a D. IMO, it's best not to focus on what will happen to the marriage. Work on becoming a stronger you, and view your H not as your spouse, but as a flawed human being. This is where the OW have an advantage...they expect less, and give the men what they need. One thing my H has said to me is that I made him feel like I just needed him to complete the picture of husband and father; he wanted to feel like a special person and was hurting inside. He couldn't stand up to the pressure of marriage because it felt like a " thing" to him and he was getting lost. He had to build from the inside out, and come back to me in a mature way, to feel the joy of marriage rather than the confinement of it. He is still working on this...just as I am working on forgiving the past to create a new future.
Take care of yourself, let go of the marriage, and you may be able to see your H through different eyes, and with genuine love, beat OW ( if there is one, I will go back and read your story) at her own game.