Ok OS2 I am going to tell you how to salvage your M because I think you have a chance.
You’ve only been married for 4 years so there isn’t enough resentment built up or else you would be toast. Right now her emotions are telling her to be with OM while her logic and reason is telling her she is married to you. A woman makes her decisions on based on emotions and uses logic and reason to justify her decisions. The longer this goes on and she builds a connection with the OM the slimmer your chances get. She can’t rebuild her relationship with you while she has feelings for him. You can’t control her actions so what can you do? You get a life like a mad man and you don’t sit around and wait for her to come by and give you scraps. For this to change she has to think that you’re not sitting around waiting for her to choose.