One final way that is most helpful in dealing with anger is to Make an Anger List.
Write everything down that you are upset about. Get it out of your head and onto paper. It could seem like this list is a way to 'keep score'. You know, make a giant list and keep track of every fault your spouse has or mistake he or she has made and pull it out when it suits your purposes. The opposite is actually true.
Making this List is a way to clear the air in your marriage. Usually when dealing with an affair there are lots of past slights that never were discussed. They are just hanging out there causing chaos in your relationship.
Each person should make a list. There is the anger from the betrayed about the affair and other happenings over the course of the relationship. There is the anger of the offending spouse over the course of the relationship that may in some ways have contributed to the affair. There is almost always unresolved anger at least partially behind an affair. Remember, the affair is a bad way of communicating something to the other spouse. Part of that something typically includes anger over some significant part of the marriage whether the person having the affair was totally aware of it or not when the affair began. Also, recall that just because a person doesn't look angry doesn't mean that person is not angry. Anger is present behind many facades.
Making this List is a beginning point of having constructive talks about the anger in the relationship. After the list is made rank them. Use the speaker/listener technique to talk through a few at a time with your spouse. Don't try to go through all of this in one sitting. There will be tension in these conversations so do your best choosing a time when you both have energy to focus and be present. While there is risk in doing this, I trust you will each learn more about the other. In this process I hope safety will grow in having difficult conversations with one another. This in turn will make it more and more possible to be vulnerable and get to a place of talking more about the hurt underneath the anger and eventually getting to a place of grieving these losses together.