Hello! My son is 3 years old and doesn't talk very well. He's also ver…

Hello! My son is 3 years old and doesn't talk very well. He's also very nervous. I only give him calls occasionally and don't let him sit in front of the TV. At night when he sleeps, he makes grinding noises with his teeth. Is this normal? What vitamins are good for such an age? We recently had chickenpox and took anti-inflammatory drugs. Our immunity has decreased. Thank you for your answer.