what do you think I should do about my 19 month old son and his behavioral problems

I am concerned about my 19 month old son and he still has not learned to talk, well when he was 10 months old he started to talk he said 3 words, mama, dada, and thankyou, and he all of a suddent stopped and all he does is scream at the top of his lungs at me, throw things at me, bang his head against walls, and floors and gets mad he has to have the doors shut, constantly has to be held, will scream and hollar and hold on to your leg until you pick him up.  He never sleeps all during the night, never has.  He wakes up an wonders and thats scares me I can't put him in a playpen, or hold him down to make him go to sleep that makes it all worse, I just don't know what to do.  Is it Behavioral problems or Autism, or something else, its driving nuts what should I do?

[KarenDiane]

I really don't know if that could be autism or not. Have you talked to his Dr?