I have found that Marriage Counseling works well when couples are encountering normal everyday problems that seemed to have stopped their marriage but in your case with an affair I believe that each of you need to see (individually) an infidelity counselor. You need one to deal with the feelings of what was done to you and he needs to understand why he did this. Once through that if the decision is made to stay together he needs to be in recovery for several months before joining together in marriage counseling if it is decided by both of you to stay together. He chose to have an affair and it is YOUR choice now not his whether this marriage continues because you have to let go of what was done. Please get an individual counselor who specializes in infidelity counseling--I think this will help sort out your feelings--you need this after what you have been through.