at the end of the movie, is brando suffering from malaria?

No, because Martin Sheen's character kills him.

and people suffering from malaria can't die?

He isnt suffering from malaria he just felt it was time to end it all. Read heart of darkness rev

He wanted someone to take his place. Thought Id add that to the mix

didn't he just go nutty bcz of the war?

I did read heart of darkness

that was the novella that inspired the movie
...i didn't read it but didn't it take place in the congo?

yes.

Now, if y'all wanna REALLY know a bit of trivia this is my favorite movie OF ALL TIME. I can watch it again and again and again and never get sick of it.

Citizen Kane? Pshaw!
Star Wars Episode Four (the first one)? Balderdash!
Showgirls? Well, debatable...