My wife admitted committing adultery. I still had feelings for her, especially her soul. After an argument one evening, I tried to comfort her. We had intercourse, but then on the next two occasions it was as if he was in the bed with us. I haven't been able to get it off my mind. She even kissed me in a way different from 20 years of marriage. It continues to be on my mind and I can't put it away. He lives in the neighborhood. Is divorce still valid for adultery? What about my remarrying?
A similar question was asked earlier. See "If a woman accepts her husband back in desperation, can she later divorce him?" Reading the Greek carefully, I find that the exception clause in Matthew 5:32 and 19:9 are written in a tense that indicates the guilty party is actively involved in sexual sin and is unrepentant of it. If she has turned from her sin and you have forgiven her of it, then it is past history. To divorce her at this point is to declare that you did not mean what you said when you said you forgave her.
The fact that it haunting you is a statement that you haven't truly forgiven her. It is that, which you need to work upon. "For if you forgive men their trespasses, your heavenly Father will also forgive you. But if you do not forgive men their trespasses, neither will your Father forgive your trespasses" (Matthew 6:14-15).