There's a book called "Cracked" about a detox. In it, a woman tape recorded her verbally abusive husband and then played it back to him when he was sober. He then railed against her for hiring someone to impersonate him!
Much of what he's doing is because of the alcohol. The fact that you're scared of him says a lot, but it seems he's going to yell no matter what you do. Unless he has to know where you are all the time, you can get to a meeting without him knowing, but whatever you do, know that the ball is in your court. He's in a hellish state right now, and he doesn't really know what he's doing, though he thinks he does.