Hi, I'd like to help you with your question.
I am sorry you are going through this with your marriage. It is heartbreaking and a shock when you learn your husband has strayed. You mentioned in your previous post that you are interested in reconciling with your husband. You also mentioned that your husband is not interested in therapy.
It sounds as if there is something going on with your husband. Married couples can have problems in their marriages, but there are ways to work out the problems without turning to others outside the marriage. Therefore, this issue is something your husband is dealing with. There is a time during midlife that men do go through a period of hormonal changes and adjustment. They often reevaluate their lives. This may be where your husband is at right now. Here is an excellent article about it to see if it fits your husband's situation- http://www.webmd.com/healthy-aging/guide/midlife-crisis-opportunity. If this is the case, then this may be what he is experiencing and can explain his behavior.
It is difficult to fix this without a counselor's help. I agree with Bill, it would be best for you both to attend marital counseling. However, since your husband is unwilling to do so, the best way you can try to work on your relationship is to talk. If your husband is willing, set aside some time each day to talk to one another. Ask him what he is feeling. You are trying to be open and responsive here without being too needy. Let him know that his actions hurt you and that you consider the behavior damaging to you and your marriage. Say this in a neutral and firm way.
Also, start caring for yourself. This has been a blow to your self esteem and you need a boost right now. Allow yourself to cry. Surround yourself with supportive friends and family, see a counselor yourself to help you, pamper yourself and most of all, be independent. Depending on your husband or becoming needy is a deterrent to your relationship right now.
There are several books that can help you right now to work on your marriage and help save it. One is called My Husband's Affair Became the Best Thing That Ever Happened to Me by Anne Bercht. Another is How to Get Your Lover Back: Successful Strategies for Starting Over (& Making It Better Than It Was Before) by Blase Harris. Also, Back from Betrayal: Saving a Marriage, a Family, a Life by Suzy Farbman, Burton Farbman, and Marianne Williamson. You can find these on Amazon.com or your local library may have them for you.
I hope this has helped you,