Vana, I want to welcome you to the forum. Also, I have bumped some educational threads about encephalopathy (caused from high ammonia levels and treated with Lactulose) and one about the stages of liver disease. I hope you will read these, along with any other educational threads that may be of interest and help to you.
There is a lot of good information on this forum, and the best thing you can do is to become very educated about the disease. Is your husband under the care of a hepatologist? If not, he should be. ER and primary care doctors are not equipped to deal with liver disease. Also, a hepatologist can refer your husband for transplant evaluation. It may not be too late right now. It sounds like his worst problem is encephalopathy right now, but he needs a good workup.
I have never heard of distilled or spring water being bad for liver patients, unless one is retaining water or has been restricted as to fluid intake. If your husband's feet, legs, and/or belly are swollen, he is retaining water and likely has ascites. Diuretics ("water pills") are generally prescribed for this, and sometimes fluid restriction.
You asked about diet. Restrict or completely eliminate red meat as it is the most difficult type of protein for the liver to break down. Fish is good and chicken is fine. Lots of fresh fruit and vegetables will be of great benefit. If he hasn't much of an appetite, try Ensure or even Slim Fast (I like Chocolate Royale.) These have calories and many vitamins and minerals. Low-sodium V8 juice or V8 Fusion is good. Puddings. Anything with calories and nutrition that you can get him to eat, even if you have to feed him yourself.
The most important piece of advice I can give you at this point, Vana, is to get him under the care of a hepatologist, if he isn't already. And also remember to take care of yourself...take time for yourself or you will burn out fast in the days and months to come.
We look forward to hearing more from you.