| | Re: Terrible wife.
You really need some counseling, stat. You are sending yourself a lot of seriously destructive messages. You are NOT terrible. You have made some poor decisions.
You say that you know he loves you, but he's abusive, he threatens you all the time, he refuses to live within your means and then blames you for your credit problems -- doesn't sound very loving to me.
No wonder you are unhappy. I'd love to see you talk to someone who can help you think your way through it. If you cannot afford counseling (quite possible), check into some free resources -- some unitarian churches offer free counseling, and they are unlikely to be judgmental.
I would argue with the other commenters -- do NOT tell him about the affair at this juncture, not if he is potentially abusive.
I wish you luck, and please do let us know how you are doing. As the commenter above said, if you feel that he will physically harm you, get out. There are plenty of resources for battered women.