I also want to throw out there that I doubt your a bad person. You have just allowed yourself to make some incredibly poor choices. I'm sure your husband is just as responsible for allowing your marriage to get to the state that it is in, he just isnt responsible for your affair. If you dont love him and you feel therapy wont work, let him go. The shame, guilt and self-loathing you feel now and will feel after he finds out wont be worth it. Once the fantasy wears off with this new guy, what then?

I wish you well.