Unwanted mental tension. Get rid of it.

A beautiful woman came to live apposit to my house. She flerted to me and we exchanged our nos. and started taking over phone than we had physical relationship. After few  months I observed that she was also in relationship with one of my neighbors. (Though I don't have any proof) Than qurrels started between us. One day in extreme anger a informed everything to her husband and ended up my relationship with her. Now I feel she is freely enjoying with that neighbor. I check them on Truecaller and most time their phone get busy (Truecaller shows on call). I often think to harm them. I am unable to concentrate either on my work or on my family. My all time goes in checking and thinking about that. Please suggest how to get rid of it.