Hi, I'd like to help you with your question.
Has something happened recently to make you feel insecure? It does not necessarily have to be something in your marriage. It can be something at work or in other personal situations. Oftentimes, feeling bothered about your spouse's past can be triggered easily because it is about insecurity and not about her past.
When men feel insecure, it can be intense. Men focus on feeling adequate in relationships. They want to provide and to protect. They also want their partners to focus on them. They don't appreciate competition. So feeling insecure can make you aware that at one time, your wife's focus was elsewhere.
How is your relationship with your wife? Have you both been close to each other or have you started having difficulties? This can cause you to feel you might lose her and things in her past would begin to bother you.
If everything is ok with your marriage and you have no reason to believe there is anything wrong, then the issue is with how you feel. Keep in mind that your wife is with you now. Fourteen years together shows that you are both devoted to each other and care for one another. Your wife left those previous situations to be with you. And she has proven she is done with her past by staying with you all these years. If you have no reason to believe anything has changed, then your wife intends on staying with you always.
Because you feel this problem is interfering with your life and relationship, some brief counseling should help you put it all back into focus. To find a therapist, talk to your doctor for a referral. Or you can search on line at http://therapists.psychologytoday.com/rms/.
Here are some resources to help you:
Self-Compassion: Stop Beating Yourself Up and Leave Insecurity Behind by Kristin Neff
Self-Esteem: A Proven Program of Cognitive Techniques for Assessing, Improving, and Maintaining Your Self-Esteem by Matthew McKay and Patrick Fanning
If This Is Love Why Do I Feel So Insecure? by Carl G Hindy, J. Conrad Schwarz and Archie Brodsky
You can find these books on Amazon.com or your local library may have them for you.
I hope this has helped you,