Doc, I completely understand your anger. I urge you not to let it tkae control of your life. It is hard because the hurt is still compounding. I urge you to take some time to gain clarity about what you really want. Talk to your counselor, pastor and trusted friends. In other words, and I can speak from experience on this, you have been treated unfairly, betrayed and lied to, but does acting from aggrieved status get you what you truely want?
IMO, if you confront her with less than iron clad proof, all you are going to get is stonewalling and anger. It is a very unsatifying feeling. and she will turn it around on you soo fast. She has the benefit of knowing what your intentions are, so she knows how to manipulate you. So if you decide to confront, be fully prepared for the it to end up in your lap. If you have a level of proof you deem sufficient, don't expect to feel better after confronting your wife to make you feel better.
Do not get me wrong, confrontation is necessary. But do so on your terms in the manner and method of your chosing. Although it may not seem like it, you are the one that is in control here. Don't let the infidel or the feelings that terrorize you dictate your actions. That gives up too much of your hard won power.