Camera drag move

I made a script to move the camera using the mouse(i want whatever i point my cursor at to remain at cursor position while draging)

the script moves the camera but it's very jittery

  private Vector3 start;
     private Vector3 end;
    
     void Update()
     {  
         RaycastHit hit;
          Vector3 distance;
 
          if (Input.GetMouseButtonDown(0))
          {
              if (Physics.Raycast(Camera.main.ScreenPointToRay(Input.mousePosition), out hit))
              {
                  startCameraPos = Camera.main.transform.position;
                  start = hit.point;
              }
          }
          if (Input.GetMouseButton(0))
          {
              if (Physics.Raycast(Camera.main.ScreenPointToRay(Input.mousePosition), out hit))
              {
                  end = hit.point;
                  distance = end - start;
                  Debug.Log(distance);
                  transform.position = startCameraPos + new Vector3(-(distance.x), -(distance.y));
              }
          }
     }