We can all certainly relate to everything you are going through. A lot of this stuff is very predictable and usually follows a similar pattern.
LH absolutely nailed it. Read his post over and over again and let it sink in.
I would also caution you that if your wife is out drinking and going to new classes etc, she might have her eye on another man. Prepare yourself mentally for this.
This will be one of the hardest things you go through but you can and will survive and even come out stronger in the end.
