I hope you read this because you have quite a few things pointing to your liver. I was going to ask about liver function testing for hyperammonemia due to protein malabsorption: (Also Coagulation tests, Measurement of acetaminophen levels, Viral serologies.)

Any GI bleed increases blood ammonia. Drinking and smoking exacerbate the issue. Just noted you said it got worse after drinking. Lose taste? Possible. Twitching and contractures with your nervous system in trouble besides your fluid loss. It would come and go.

Definitely would cause some head "fog" as well as other metabolism problems you mention: Dehydration, Lethargy, Rapid respiration, Decreased muscular strength.

This can be very serious. (edit: I'm just a bro in nursing school, not an expert)

http://www.primehealthchannel.com/hyperammonemia-causes-symptoms-diagnosis-and-treatment.html http://medical-dictionary.thefreedictionary.com/Liver+function+tests

Edits: everywhere after I put on my sleuthing hat.