It's an interesting question.
A slow death with all the pain and hurt that is involved when dealing with betrayal, lies, utter dishonesty, kissing and cuddling another person (and the rest), or sit it out and allow the PA to fizzle out and then have doubts about feeling second best once the 'fog' lifts. Best to be a hybrid and do both. Nonetheless it is a difficult call. May be best to dust up and try to do things for yourself because you now can!
If your heart is still with your significant other he should notice any change in you.
Neglect and meanness can destroy a good relationship. Chat rooms and online fantasy lovers can have a detrimental underlying effect on how we behave.
This might help effect change Video 1: Why Emotions Matter
There are a series of videos, all of them worth watching.
Best of luck. Hang in there. Don't give up.
Just feel better about yourself and don't forget non verbal emotions. An affair person can say nasty words out of anger and resentment and other issues but, sometimes their non verbal actions suggest the exact opposite of what they are saying.