All your basic info can be found on that site. Like Parvo, Distemper can't be treated directly, you can only support the pup while his body fights the virus (for example through use of antibiotics and the giving of fluids). Unfortunately many pups just up and die suddenly regardless of how well you treat them, and if they do live, often have residual effects (like neuro facial twitching).
Keeping him alive is ultimately your decision. He would probably be immediately euthanized in shelter, since both illnesses are highly contagious and deadly.
For what its worth, i took in a stray mom who had five pups who contracted distemper while she was pregnant. Only two survived-the first doed at two weeks, the second was healthy seeming until he got the twitch and declined overnight, the third we busted our backs over trying to keep him going, but put him down when his pneumonia bested us. The other two never showed clinical signs and are happy dogs just living their lives.
Best of luck and I'm sorry your pup is going through this.