Sunshine,
I am sorry you and your family are going through this. It was suggested to you to attend al-anon I would also agree and if possible bring mom and dad. It does sound like your brother is in denial and it's sad that there is not much you or your family can do for him right now. I would also suggest you offer his wife as much support as possible. I'm sure it was very hard for her to open up and tell all of you, it must have been building for some time and she needed a release.