The first thing you need to ask yourself is this and I believe you already know the answer due to having stated it: You know your wife is involved with someone else, so can you trust her? Can you 100% fully trust her? If she goes shopping and gets "held up," or is "running late" or whatever - will even a smidgeon of a doubt enter your mind? And, if it does - then that is no way to live.
Take this time to work on yourself. Maybe ask yourself is the reason you are trying to hang on so hard is for purely selfish reasons and not the bigger picture. An affair is the ultimate disrespect a spouse can do.
There are moments in this life when you are so confident in the rightness of your actions, that not even for a second do you consider the option that you might be wrong.
