Spooky, welcome to the forum. I am sorry to hear about your parents' medical problems. It would seem to me that your dad is a "closet" alcoholic; i.e., able to hide his drinking quite well, but has been drinking a lot over a long period of time to end up in this condition. The "being out of it" that you described is probably hepatic encephalopathy, where ammonia builds up and goes to the brain. They usually prescribe Lactulose or Kristalose for this, which must be taken daily. The ammonia is excreted through bowel movements. The most important thing for him to do is to stop drinking completely. This is absolutely necessary for him to have any chance of survival. If he is unable to stop on his own, he will need to go to AA or to alcohol counseling. Should he need a liver transplant, they will not even evaluate him until he has documented sobriety of 6 mos. Also, if he does not stop drinking, your mom would have to be cared for by someone else. It could be that the stress of caring for her led him to start drinking more than you thought he was.
Try speaking to his doctors or nurses to get a full assessment of his condition. When he gets back home, it would be helpful if he eliminated beef and has a diet rich in fresh fruits and veggies. Also, he should not be taking anti-inflammatory meds like Tylenol on a regular basis, as they are harmful to the liver and kidneys.
The most important thing, though, is that he stop drinking completely. Hopefully, he will have quit in time.
I suggest you read some of the older posts here regarding alcohol and liver disease, and also read the info in the folder at the top of the page entitled Hepatitis Resources. The best thing you can do in this situation is to become educated about liver disease.
Forum moderator - Hepatitis
"But that was yesterday, and I was a different person then."
Lewis Carroll, Alice in Wonderland