Take it down, one block at a time. Ask your child to make another tower. Some children cannot do this until they are older. Don't worry if your child needs more time or more practice. Be patient and encouraging and stop the game before your child is bored or frustrated.
Children learn language best from someone who speaks it well.
Since you can speak your native language well, speak to your son in your native baby language. Help him learn it as well as he can. Later, when he has a chance, he can learn English from someone who speaks English well. He willlearn to speak English more easily after he has become skilled in your language. Raising a toddler can make you feel really uptight sometimes.