Congrats on your sobriety, WhiteRhino.
You've gotten great advice from this side of the street. I think a key we look for as the F&F of A's is ACTION. Your words mean very little at this point. The action we look for is recovery work - treatment program, AA, sponsor, working the steps, counseling, etc. You may be sorry for the things you have done, but saying "I'm sorry" will not cut it now...you have to live sorry - that's making amends for the past behaviors.
MountainMan spelled it out very clearly...take care of yourself, take care of your family & personal obligations, turn it all over to your HP. As you do have children, you & your wife will continue some sort of relationship. When time has passed and your actions are speaking for themselves, you may be able to request couples counseling to see if you can come back together. Maybe you can, maybe you can't. For now, let her go work on herself.
As for her friend...it is her choice who she confides in and trusts now. Someone that has a close A family member is going to be a trusted confidant because they know or understand better what she has gone through with you. Her friend is not the problem. Your wife is grieving her marriage - her hopes, her dreams, etc. She is dealing with the emotional & mental fallout of alcoholism. It is painful and heart wrenching, even without physical abuse.
For now, keep working on you. Thanks for your post.