Hi, I'd like to help you with your question.
There is nothing wrong with how you feel. An affair is devastating to a marriage and to the husband/wife who is the victim. Getting over the affair takes a long time and very hard work. You never quite forget it but it becomes easier to live with.
You have the right to ask any questions you need to of your husband. When you both married, the marriage was meant for the two of you. He chose to bring someone else into your relationship and you have the right to know anything you need to about that relationship. It helps break down the separation between you and your husband if the truth is known and he is not able to make the details of the other relationship only between him and the other person. In other words, if you know all the details you want to know, then the relationship they had is no longer just between them. Also, knowing what happened helps you to keep your imagination from taking over and making the situation worse.
Your husband wants the affair to go away because he most likely feels guilty about it. When you bring it up, it reminds him that he was wrong. This is hard for him to face. But it is important that he faces it now so he does not make the same mistake again.
It is also important that he is sorry for what he did and that he works very hard to earn back your trust. He cannot just say he is sorry and move on. This is not enough to insure you are ok and that trust, the most important factor in a stable relationship, is reestablished.
To rebuild this trust, you should do what you need to feel better. If that means calling your husband anytime you feel you want to know where he is, then he needs to accept that. If you need to be aware of what he is doing each day and who he is with, that is ok too. The idea is that he proves he can be trusted and you are able to trust him again enough to not have to do this.
Also, if you feel the therapist you worked with was not helpful, seek out another one. You need someone you can work with that addresses your concerns and helps you deal with your feelings about what happened. Talk with your doctor about a referral. If you attend church, speak with your pastor. Pastors and their staff are often very good with marital issues. You can also search on line at http://therapists.psychologytoday.com/rms/.
You can also help yourself through books and resources. Here are some to help you get started:
Infidelity: A Survival Guide by Don-David Lusterman
Surviving Infidelity: Making Decisions, Recovering from the Pain, 3rd Edition by Rona B. Subotnik and Gloria Harris
My Husband's Affair Became the Best Thing That Ever Happened to Me by Anne Bercht
You can find these on Amazon.com or your local library may have them for you.
Remember, you are doing fine. This is not an easily solvable problem so it will take a while, maybe even a few years. Give yourself time and do what you need to feel better.
Let me know if I can do anything else to help,