Sounds like everyone is giving you great advice and you seem to be on the ball with all this. I drank protein milkshakes when I was having the same issues. My appetite was meager at best. The sodium issue can be a difficult thing to get through and for me it harder than quitting alcohol. I wasn't hungry to start with but what I considered bland salt less meals made it worse. I lived on protein shakes, bananas and peanut butter. Diuretics can be hard on the kidneys so just keep that in mind as far as dosages. A lot of guys who take diuretics experience testicular swelling also, be sure to watch for that. GI doctors can be very good for the in between visits but he really needs to see a Hepatologist.
Ziff