How To Handle Relationship Problem?

hi I ve been with the same women for 23 years, married 2 years. Almost from the start she cheated on me. I helped her raise her child. she would run to dance clubs with her friends. Sometimes she wouldn t come home to 6 in the morning. she would say she slept on their couch. I have not had sex with her for the last 18 or 19 years. All she cared about was running out when her daughter was with her ex. I know at least 2 affairs she had. I had health issues, and had a heart transplant 2 years ago. I am retired and have lots of time on my hands, and I can t stop thinking about her with other men. She is now more affectionate towards me and acts like nothing happened. she has never admitted to me that she had affairs, but I know she did. thinking about her with those other men is tearing me apart. what can I do, she will never talk about it with me.