Deleting a linked list node using two pointers

I know there are other approaches to delete nodes, but I couldn't figure out why mine is wrong.
I want to know at what step I made the mistake. Thank you in advance

Given a linked list called "items" that contains 5 nodes with the following data: 1 2 3 4

Goal Delete the last number ( 4 )

Code

        nodeType *p=items,*q;
        while( p->link!=nullptr)
        {  
           p = p->link;   
           cout << p->data << " ";  
        }
          // Output of the loop: 2 3 4  ("1" isn't here b/c "p" is overwritten)
          // p == address of the third node's link
          // p->data == 4 

        q = p->link; // q == the address of the node that contains 4
        p = nullptr; // unlinking the third node from the fourth node.
        delete q;   // deleting the last node ( that contains 4)

        cout << items->link->link->link->data; 
        // Output: 4 

Question
HOW COME NUMBER 4 IS STILL HERE ?!