I suspect that my wife of 20 years is having an affair and it’s killing me

I am a doctor. I have been married to a nurse for 20 years and we have been blessed with four children. I have a problem with my wife as a result of rumours circulating around the hospital. Word is she is having an affair with a male nurse. This information is in the public domain. I have no evidence so far but I get information especially when they go to seminars that they are often spotted in compromising positions. I am embarrassed and depressed about this that I sometimes just break down and cry. Even my daughter is aware of this situation. She denies it every time I ask her about this and so I don’t know what to do. I just want to divorce her yet I don’t. I am confused and depressed and need your advice on this. Please help.