How do you make the bad thoughts stop? 

I wish someone could tell me how to make all of the bad thoughts go away and stay away.  I am the type of person who wants to know all of the details about something before I make a decision.  Well when it came to finding out my wife was cheating I started asking questions.  I can still see the images of the text messages I read and the emails I read as if they were in front of me now.  I still remember her lack of emotion or regret as she told me the details.  I just couldn't stop asking questions.  How did it start, who started it, where did you meet, how often did you talk to him, how often did you sleep with him, did you use protection, well you get the idea.  She finally stopped answering my questions but now my mind is left to wander down the darkest road to nowhere.  My mind constantly creates worst case scenarios and replays them in vivid color.  I can't take it.  I can't talk to her about it because it starts an argument.  I am just left to suffer the torment of my mind.  What I hate the most is that I love her unconditionally and I have taken her back on her word that things are over.  However there are times when we are together that I am almost physically sick because I can picture the two of them together and know that she once referred to him as her boyfriend and told me that she loved him more than me and that she wanted a divorce.  I know I am just venting and this probably makes no sense at all but I have gotten to the point where nothing works anymore.  Meds don't work, therapy doesn't work, meditation doesn't work.  I just want the past to go away and leave me alone so I can work on the present.  This has sucked all of the fun and enjoyment out of my life.