Object follow touch more faster and accurate

I've searched a lot to solve my problem but with no success. The problem is next:

I have a sprite with circle collider and I want to move it under my finger to dodge some other objects. I make it to move buy the problem is that it's moving too slow. Sprite IS FOLLOWING finger but too slow and IS NOT under finger when I move finger fast left-right. My code is:

 public class PlayerController : MonoBehaviour {
 
 private Vector3 position;
 private bool isTouched;
 
 private RaycastHit2D hit;
 
 void Awake () {
     isTouched = false;
 }
 
 // Use this for initialization
 void Start () {
 
 }
 
 // Update is called once per frame
 void Update () {
     if (Input.touchCount > 0) {
         if (Input.GetTouch(0).phase == TouchPhase.Moved) {
             hit = Physics2D.Raycast (Camera.main.ScreenToWorldPoint (Input.GetTouch (0).position), Vector2.zero);
 
             if (hit.collider != null && hit.transform.gameObject.tag == "Player") {
                 isTouched = true;
             }
 
 
             if (isTouched) {
                 transform.position = Camera.main.ScreenToWorldPoint (new Vector3 (Input.GetTouch (0).position.x, Input.GetTouch (0).position.y, 5));
             }
         }
         if (Input.GetTouch(0).phase == TouchPhase.Ended) {
             isTouched = false;
         }
     }
 }

I found same question on this site:

http://answers.unity3d.com/questions/898484/how-to-make-your-object-follow-your-touch-position.html#comment-898488

But there is no answer.

Please help!