I can't find the gameobject that my scriptis attached to

I keep getting the error NullReference Rxception and when i click on the error it takes me to the first line in my update function. I tried changing it to transform and I'm unsure what to do now.

 Transform myself;
 GameObject Player;
 
 void Start ()
     {
         Player = GameObject.FindGameObjectWithTag ("Player");
         myself = gameObject.transform;
     }
 void Update ()
     {
         myself.position = Player.transform.position;
         myself.rotation = Player.transform.rotation;
         Debug.Log (gameObject.name);
 
     }