I am not really sure what to say. I wish I had followed my husband when he left the house and found out exactly what he was doing because I trusted him so much - then he would end up seeming inebriated with no actual evidence of drinking. I think you are wise to privately work out what he is consuming but are also wise to already know there are things not to do when you come to confront the issue. I did absolutely ALL the wrong things with mine and became quite the worst kind of codependent. Ended up really hating myself for a while back there.
You have found a great source of support and advice here. I haven't been here long but it has turned my world around.