It doesn't sound as though he is easy to help.....doesn't like smooth food, doesn't like lumps, doesn't like milk or milky drinks.
I do feel sympathy for him, but he has to get a hold of himself and make an effort too.
It sounds like he is angry (and who can blame him, he's been dealt a lousy hand) but going in the huff about eating things and upsetting his wife, family and friends who are all upset enough already is not the way forward .
Maybe the opportunity to talk things through with someone outside of the family might help. A MacMillan nurse, perhaps ?