Do both of you want to save the marriage?
Two kids might not be enough of a reason. I'd think twice about whether it was this relationship you want to save. This relationship hasn't allowed her to approach you to talk about what she sees as issues in the relationship. This relationship hasn't allowed you to see a woman driven far enough outside her usual comfort zones to consider having an affair without discussing problem areas first. To go back to this relationship would hardly be a dandy idea. To make this thing work, the two of you are going to have to create a new relationship for yourselves with different ways of dealing with each other built in as a matter of both comfort and choice.
Going back to what you've got now is a losing proposition. It doesn't bring joy to either of you.
You need to know what has closed her down to the relationship process when the process has most needed openness from both of you. She needs to know what's made you difficult to address with her concerns. Is it only your wife, or is it possible other folks may have trouble talking with you? Is your wife this frightened in all situations, or is it only certain kinds of situations that make her shy about talking?
Why no see if you can find some good couples' counseling? And try to imagine what kind of a relationship both of you would be thrilled at being in with each other. Why settle for the stuff that made you this uncomfortable in the first place? Why not ask yourselves, both of you, what would make this the relationship of your dreams. What would you get from each other and what would you give?
There's nothing wrong with some appropriate suffering here; as long as you let it motivate the two of you into working out a healthy and reasonably happy solution, the suffering can be quite productive. There are loads of good counselors about. Check out one or two until the two of you find somebody you can both work with productively. If things work well, you'll both come out of this feeling more alive and hopeful. No reason that shouldn't happen.