A cheat is a cheat. An alcoholic is an alcoholic. One does not make you into the other. I know plenty.
I question your opinion of an emoational affair. An emoational affair to me means no contact, just involved on an emoational level. If they had "some hugs and pecks," I would say you know the tip of the iceberg. That crossed the line into emoational and physical IMO. Same result, cheating is cheating.
I would say that you need a counselor for you, she needs one for herself. You may also want to try Alanon or Celebrate Recovery as it sounds like you could use some support from people who understand what you are dealing with. CR helped me through a very dark place.
I will be honest, I believe the saying a leopard does not often change their spots, but that is just my own opinion and from history of what I have seen here on SR and in my life.
No matter what decisions you make, take good care of YOU. We will support you.