mouse to sensitive, moving to fast

i am moving this object with the following code...
this code is attached to a parent of the camera..

Code (CSharp):

1. void Update()
2.     {
3.         if (Input.GetMouseButtonDown(2))
4.             GetMouse = false;
5.         if (Input.GetMouseButtonUp(2))
6.             GetMouse = true;
7.         // if (Input.GetKeyDown(KeyCode.LeftShift))
8.         //    CameraDisabled = !CameraDisabled;
9.  
10.         if (!GetMouse)
11.  
12.       {
13.             float distance_to_screen = Camera.main.WorldToScreenPoint(gameObject.transform.position).z;
14.             Vector3 pos_move = Camera.main.ScreenToWorldPoint(new Vector3(Input.mousePosition.x, Input.mousePosition.y, distance_to_screen));
15.             transform.position = new Vector3(pos_move.x, transform.position.y , pos_move.z );
16.  
17.  
18.         }
19.     }

but if i move the mouse slightly i already get a big movement, but i can't figure out how to add in the sensitivity.

please help.

 

i used the lerp function:

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class CameraPan : MonoBehaviour
6. {
7.  
8.     public bool GetMouse = true;
9.     private Vector3 newPosition;
10.  
11.     //private Transform cam;
12.     void Awake()
13.     {
14.         newPosition = transform.position;
15.     }
16.     void Update()
17.     {
18.         if (Input.GetMouseButtonDown(2))
19.      
20.              GetMouse = false;
21.          if (Input.GetMouseButtonUp(2))
22.              GetMouse = true;
23.    
24.           if (!GetMouse)
25.         {
26.             PositionChanging();
27.         }
28.  
29.     }
30.      void PositionChanging()
31.       {
32.             float distance_to_screen = Camera.main.WorldToScreenPoint(gameObject.transform.position).z;
33.             Vector3 pos_move = Camera.main.ScreenToWorldPoint(new Vector3(Input.mousePosition.x, Input.mousePosition.y, distance_to_screen));
34.             newPosition = new Vector3(pos_move.x, transform.position.y , pos_move.z );
35.  
36.             transform.position = Vector3.Lerp(transform.position,newPosition, Time.deltaTime);
37.  
38.  
39.         }
40.  
41.  
42.  
43. }

not exactly what i wanted..wanted a drag...but this will do..