Originally Posted by memorable
I feel I should make him feel the pain I 'm going through then I would have settled the score with him.
First of all, you said that you have a "feeling" that he cheated but you don't have any proof of it. It allegedly happened a really long time ago so how do you know? You don't seem to know for sure. For you to go off on a random affair to get back at your husband for something that he may not have even done shows very poor character on your part. Do you really want to be that person? And how will you feel if you find out he was telling the truth that nothing ever happened with someone else but you'd already had your little affair? How would you live with yourself?
Secondly, this attitude of yours is the most unhealthy way possible to deal with a marriage problem. Your marriage is severely lacking in open communication, which is a requirement for a healthy marriage. What you should be doing instead of planning revenge is talking to your husband and sharing your fears and concerns with him in a loving and open way so that you can both be on the same page. All of this behind his back stuff is juvenile and will blow up in your face, guaranteed.
Third, your best option for getting all of this behind you is to go for counseling. You can start out going alone but you may want to eventually go with some couples counseling. But you might find that the problem is all your own and that the individual counseling will actually in the end help you work your way through this. Either way, I suggest counseling before a worthless affair that will only make things a lot worse than better.