BST Add word Node

So I am trying to make a BST function that adds words from a .txt file. I want the function to add word, with the first letter as a sibling and all following letters as children. If a word has already been entered I don't want to reenter the word onto the tree, I just want to increment a variable that indicates there is more than one of these words.

So the code that I have just prints This(the first word in the .txt file) over and over again. It doesn't appear to get past 't' in this though. How would I make it go to the following letters in word?

Code:

---

Node::AddAWord(char word[])
{
 
 cout<<word<<endl;

  if(letters!=*word)
  {
    if(sibling==0)
    {

      sibling=new Node(*word);
      sibling->AddAWord(word);
    }
        else
        {       
               
                sibling->AddAWord(word);
        }
  }
 
  else
  {
          if(child == 0)
          {       
               
                 

                // cout<<word[k]<<endl;
                  child=new Node(*word);
                  child->AddAWord(word);
                 
          }
 
 
        else 
        {
                // cout<<word[k+1]<<endl;
                  child->AddAWord(word);
       
        }
        }

 
}

---