I'm sorry to hear that he is flaunting this in front of you, no matter if you are sleeping in another room or not. I would feel like strangling him, or my H also, if they did that to me. You don't deserve anything else after what you have been through.
I would guarantee that If I left my H, he would not live the rest of his life alone, he would find someone. My Dad, who cheated on my Mom 3 times, had a girlfriend when she was sick and under Hospice's care. You would have thought he might want to sit with Mom, by her bedside, knowing that she was dying and eat dinner with her, but no his wrestling match's and the male Hospice worker was more fun for him. Then he goes out a buys a red truck 2 weeks after Mom died and started seeing his lady friend, who was the age of my children. It made me sick, he couldn't have even waiting a respectful time after 60 yrs. of marriage to be with the other woman?
It's all about needing attention from woman that they can't do without it. Their self-esteem from what my therapist told me 27 yrs. ago if very low and that's why no matter how good you treat them, they still need it from someone else. We as wives can't ever do enough to feed their ego, they still have to have it stroked by any other woman, sad isn't it?
I hope that you are able to get out sooner than later. That would be wonderful, what your going through has got to be hard to do. I wish you the best of luck.