I know this is a year later, so your situation might have changed for you by now, however, I’ll post this anyway. Maybe you or someone else will find it helpful.
Might it be possible you are not finding your wife as interesting because you are involved with another woman?
It's too easy to compare your feelings for both women because the grass always looks greener on the other side.
What were the reasons involved that you fell for this other woman while you are married?
Were you involved in a working relationship first? Maybe a high stressed situation?
This can create an artificial bond that would quickly evaporate if the circumstances changed.
Why is this woman involved with you?
You are a married man! Ask yourself why she would be willing to have an affair with you (emotional and/or physical) knowing you have a wife and children?
It takes time to fall in love! Initial attraction can create strong feelings, but it takes time to develop the kind of love that will last. What makes you believe she will stay the long haul with you? What if she, as you are doing now, falls in love with someone else? What makes you think she would honor her commitment to you? She is already helping you break your commitment to your wife now.
It is true that we only have so much time to live, but that is the reason why we should live our life meaningful and with purpose. "Doing only what makes us happy" can be deceptive because our human feelings can change so quickly. True you might feel the way you do about this other woman for another three years, but then again you might leave your wife for her and then wake up one morning and think "I made a huge mistake!"
Your wife made a commitment to you and you her. Is it fair to your wife that you have this other woman? Is it fair to her that she is unknowingly competing for the right to have your whole heart when she is suppose to have it already?
If you love your wife and kids then honor your commitment to your family. Work on your marriage. Find ways to kindle your romance and strengthen your bond. You already have a good thing going with your wife. If you never really fell in love with your wife in the past that does not mean you can't fall in love now. Love is a choice! Choose to love your wife and be rewarded for your effort with a loyal and strong r