@Mustang959,
Get yourself a therapist to talk to. That alone can help ease some of your anger, depression and frustration; it alone though may not be enough. Your wife will need to take responsibility for any affair/s she may have had. Try couples counseling. Even if she refuses to go, it can help you. Remember your personal well being is what is most important here. Take care of you first.
And, as Jespah advises, divorce is a very real option - and from what you wrote, I'd be out of that hellish home quicker than you could say Jack Robinson.