Sail48-
I just want to say that I agree with all the above posters. Working through this is not easy, but it does get easier with time.
I knew about my husband's drinking for a number of years. I myself was dealing with my own issues and kept saying "When I am fixed I will deal with the relationship." His affair with a friend of mine FINALLY got me healing. It finally got me into Al-anon, and though the focus of that group is working on how to deal with someone in the throws of addiction for me it really helped to deal with the affair also.
There are many books on both addictions and affairs (they helped me immensely). The big ones on affairs are Not Just Friends by Shirley Glass and After the Affair by Janis Abrahms Springs (who also has an excellent one on forgiveness that was incredibly helpful. "In all our affairs" which is an Al-anon book (about alcohol use) and other books along that type had a lot of stories that touched and resembled my story.
Be gentle with yourself, you are not alone. Sending kind thoughts your way.