Hi, I'd like to help you with your question.
First, I am sorry this is happening to you. Anytime a spouse strays outside the marriage it can cause strain to the marriage and undermine trust, which is essential to a good marriage.
It is ok that you still feel upset about what happened. You were betrayed and the trust was taken out of your marriage by what your husband did. It is normal to feel upset about it until it can be resolved. And that takes a lot of work for both of you. Your husband has to regain your trust and if he is not doing that, that leaves your marriage in limbo and your feelings unresolved.
There also needs to be clarification on some issues.
One, is your husband sorry for what he did? This is important, because if he does not take responsibility, recovering your marriage will be difficult.
Two, has your husband stopped all contact with this other person? He must do so as a first step to regaining your trust.
Three, has he done anything to start repairing the marriage? It is ok to feel upset that he doesn't have the time. He needs to make the time and make the marriage a priority.
Four, are the two of you talking about what happened? Your husband needs to be open and honest about what he did and let you ask any questions you need to. He broke the marriage vows and dragged you into another relationship. He needs to own up to it.
In addition to therapy, if you attend church, talk with your pastor. Pastors are often very good marriage counselors. And most of all, build up your supports. You need people around you who you can talk with and that understand. It will help you heal.
The other important factor is to rebuild trust. It can take a while and a lot of work, but you can do it as long as you both are motivated. Your husband must be willing to be accountable for his actions and behaviors and allow you to question him. He also needs to check in with you if that helps you learn to rebuild your trust.
There are some books and resources that may help you as well:http://www.marriagebuilders.com/graphic/mbi5525_qa.html http://www.dailystrength.org/c/Infidelity/support-group
Infidelity: A Survival Guide by Don-David Lusterman.
Not "Just Friends": Rebuilding Trust and Recovering Your Sanity After Infidelity by Shirley P. Glass and Jean Coppock Staeheli.
You can find these both on Amazon.com or your local library may have them.
I hope this helps you,