Simplify- If he is having trouble getting liquids down, then maybe it's time to ask about a feeding tube. I know it sounds awful, but many people with esophageal cancer need it. If/when he gets better, they can reverse it. At least then he'd get nutrition and liquids in each day.
I don't think loosing that much weight in 3 mos is normal, even for this kind of cancer. My husband lost 30 lbs. between getting sick and his diagnosis. Then he lost about 10 more after diagnosis due to chemo. Since then, he's regained 5 lbs and is eating pretty well. The radiation shrunk his esoph tumor down to almost nothing, and the doctor gave him meds to help stimulate his appetite. When he was having the most trouble with eating, I made him high calorie shakes 3x a day with Scandi shakes, whole milk, fruit, and yogurt (=800+ calories per shake). Just having that amount of calories and protein really helped him keep going.