Therapists like myself help people develop new coping skills, adapt to change, and grow from adversity. I make this statement to help you understand that there is no such thing as “fixing” people. However, based on the fact that you are still holding on to the pain of betrayal and being dishonest with your husband, you should seek professional counseling.
The only way to really forgive your husband is to forgive yourself. The feelings of disappointment and betrayal are internal factors that are influenced or caused by external factors. You have to learn how to monitor your internal thoughts and emotions. This is extremely important because the way in which you view your situation will determine how you cope with it. The energy that you put into feeling unhappy must be redirected and changed to reflect the life that you would rather have with your husband.
I believe that forgiveness is not only about moving forward, but is also about moving up. When you forgive yourself you become a better you. The adulterous memories will resurface occasionally and it is in these moments where you have to focus on what you have. Do not deny yourself the opportunity to grow by holding on to the past. If you look forward, you cannot get stuck in the past.
Lastly, remember that forgiveness is not a secular skill that we embrace and practice well. Forgiveness is complex to us, but is really simple if we place God in the center of our lives. Forgiveness is a spiritual skill that flourishes when God is present. As you place God in the center of your life and marriage, practicing forgiveness will get easier.