Thank you everyone for your kind replies. Everytime I struggle through these questions I will be re-reading this thread.
My story is also like "karmahappens"'s post. We were young when we got married. We got married in our early 20s and started a family. We had many struggles, mostly financial.... But through the years, never did I feel like we had grown apart. In fact, I feel we had grown closer as best friends through the experiences we shared. That's why I was very shocked about the affair.
It seems to me that one important reason why some marriages survived is because the couple fell in love again. How can it happen to us? I told WH that it will be difficult. I will not be able to look at him with the same innocence. He said he'll just keep doing what he's doing - that is be a good husband and father to our kids and hopefully my feelings will change in time.