Maximus, I am sure she suspected an affair which would be a huge motivator for her to hit the gym the way she did and to seek affirmation from another man to make her feel good about the way she looks.
You wrote "I never considered her sexually since a long time". She probably sensed this. As I said, a woman gets turned on knowing that she turns you on. The suspected affair was a huge insult to her ego. She simply wants to feel beautiful and desired. We can tell by the way you look and talk to us. Talk to her like you would a very sexy girl in her early 20s. Like she is a prize you want to win. If you were involved with someone else, I can imagine how detached you were from wife and for a long period of time too and I can imagine how bad she felt not knowing for sure but suspecting. I know you feel the affair was justified but she will never see this. She will see how hurt you made her feel and how you chose other woman instead of being patient and working with her. The way man think they work on things and communicate is different then the way women do (She is exercising to the point her Achilles tendons are about to tear...do you see the emotional pain she is in? )
I suspect the 180 in your case would be giving her attention, time, and tons of verbal affirmations? When did you give up giving her romance?
it sounds like you resent her because of no sex and she resents you for something. You might have to be bigger person (which it sounds like you are trying to be) and put your resentments to side. I'm not saying to tell her of your indiscretion, but you might want to treat her the way someone that cheated on his wife and is trying to get her back does. By swallowing your needs for a while and just rebuilding her confidence. Give her time to trust you again. Show remorse and apologize for neglecting her. Make her feel beautiful
Me: 42 H: 43 Twins age 5 Physically Separated 7/2015