Doug,
Sorry you are going through upsetting things. You didn't mention anywhere in your post if you have expressed your feelings verbally to your wife. Have you told her how you feel and asked her how she feels? It might be very clear in your mind how you feel, but, unless you tell her, she probably won't know. To me, it sounds like there are things she is feeling that you're not aware of also.
It seems like you still value many things about your marriage, and if that's the case, it could be helpful to spend some time talking to and listening to your wife. At this point, it might be beneficial to have the help of a counselor whom you both trust.
Peace and Healing,
mousewife