The OW in my marriage finally became a blessing for me. She was the one who had to deal with his late night drunken diatribes, his need for control, his need to have his ego stroked constantly. Her presence meant that I could kill all hope of reconcilliation (infidelity is mydealbreaker) in my head and he was so caught up with her that No Contact was easier to maintain during the seperation and sale of our house - though when he did break it he really tried to get under my skin and hurt me.
Now he doesn't have my phone number and doesn't know where I live he can't spill out his venom on me. She has helped keep me safe from him and I am now grateful she came along!
I hope that someday soon you will realise that an OW, even though the betrayal is incredibly painful, can actually help you move on. It took me time to realise how she was a help and counselling helped me deal with the pain - it didn't happen over night.
Take care of yourself. How they are together isn't a reflection on you. You being with him didn't make you happy. And after all, that is what really matters - finding YOUR happiness.
:ghug3