The sphere goes Slow

Hi guys I'm an experienced programmer of unity 3d I have created a ball videogame , but when I try to move the ball the ball goes slow as a snail I also tried to increase the value of the (moveSpeed = to 60 or 100) but it does not work how i can solve this problem ?

 public class Ball : MonoBehaviour
 {
     public float moveSpeed = 50;
     public bool useTorque = true;
     public float maxAngularVelocity = 50;
     public float jumpPower = 2;
     public const float groundRayLength = 1f;
     private Rigidbody thisRigidbody;
     
     private Transform mainCamera;
     private Vector3 mainCameraForward;
     private bool jump;
     private bool superspeed;
     private Vector3 move;
     private Transform defaultParant;
     
     public GameObject messageText;
     //public Text coinsText;
     private int coinTotal;
     private int coinCount;
     public bool lastLevel;
     
     //public float newZCoordinate, newXCoordinate;
     public bool inAir = false;
     
     //instances
     private CheckpointManager chkMngr;
     
     
     private void Start()
     {
         Screen.lockCursor = true;
         Screen.showCursor = false;
         
         mainCamera = Camera.main.transform;
         thisRigidbody = GetComponent<Rigidbody>();
         GetComponent<Rigidbody>().maxAngularVelocity = maxAngularVelocity;
         
         coinTotal = GameObject.FindGameObjectsWithTag("Coin").Length;
         //coinsText.text = "Coins: " + coinCount.ToString() + "/" + coinTotal.ToString();
         defaultParant = transform.parent;
         chkMngr = GameObject.FindGameObjectWithTag("checkpointManager")
             .GetComponent<CheckpointManager>();
     }
     
     private void Update()
     {
         float h = Input.GetAxis("Horizontal");
         float v = Input.GetAxis("Vertical");
         jump = Input.GetButton("Jump");
         superspeed = Input.GetButton("Superspeed");
         
         if (mainCamera != null)
         {
             mainCameraForward = Vector3.Scale(mainCamera.forward, new Vector3(1, 0, 1)).normalized;
             move = (v * mainCameraForward + h * mainCamera.right).normalized;
         }
         else
         {
             move = (v * Vector3.forward + h * Vector3.right).normalized;
         }
         
         if (transform.position.y < -5)
         {
             ResetPosToLastCheckpoint();
             inAir = false;
         }
         
         if(inAir)
         {
             //Debug.Log ("IN AIR");
             
             if(Input.GetKeyDown(KeyCode.W))
             {
                 //float newZCoordinate = .02f;
                 //transform.position = Vector3.Lerp(transform.position,new Vector3(transform.position.x, transform.position.y, newZCoordinate),Time.fixedDeltaTime * 20);
             }
             if(Input.GetKeyDown(KeyCode.S))
             {
                 //float newZCoordinate = -.02f;
                 //transform.position = Vector3.Lerp(transform.position,new Vector3(transform.position.x, transform.position.y, newZCoordinate),Time.fixedDeltaTime * 20);
             }
             
             if(Input.GetKey(KeyCode.A))
             {
                 this.rigidbody.AddForce(new Vector3(0,0,.5f));
             }
             
             if(Input.GetKey(KeyCode.D))
             {
                 this.rigidbody.AddForce(new Vector3(0,0,-.5f));
             }
             
             
         }
         
         /*if (Input.GetKeyDown(KeyCode.Escape))
         {
            Application.LoadLevel("Menu");
         }*/
     }
     
     private void FixedUpdate()
     {
         
         if (useTorque)
         {
             thisRigidbody.AddTorque(new Vector3(move.z, 0, -move.x) * moveSpeed);
         }
         else
         {
             thisRigidbody.AddForce(move * moveSpeed);
         }
 
         if (Physics.Raycast(transform.position, -Vector3.up, groundRayLength) && superspeed)
         {
             thisRigidbody.AddForce(Camera.main.transform.forward * rigidbody.mass * 10, ForceMode.Impulse);
         }
         if (Physics.Raycast(transform.position, -Vector3.up, groundRayLength) && jump)
         {
             thisRigidbody.AddForce(Camera.main.transform.up * rigidbody.mass * 10, ForceMode.Impulse);
         }
         
         //thruster logic
         /*if (Input.GetKeyDown (KeyCode.T)) {
             rigidbody.AddForce(transform.forward * 2000f);
         }*/
     }
     
     void OnTriggerEnter(Collider _hit)
     {
         if (_hit.tag == "Coin")
         {
             Destroy(_hit.gameObject);
             coinCount++;
             //coinsText.text = "Coins: " + coinCount.ToString() + "/" + coinTotal.ToString();
         }
         else if (_hit.tag == "Next")
         {
             if (coinCount == coinTotal)
             {
                 if (lastLevel)
                 {
                     Application.LoadLevel("Menu");
                 }
                 else
                 {
                     Application.LoadLevel(Application.loadedLevel + 1);
                 }
             }
             else
             {
                 StartCoroutine(ShowMessage("You need to find all the coins"));
             }
         }
         else if (_hit.tag == "Platform")
         {
             Debug.Log("Allo m8");
             transform.parent = _hit.transform;
         }
     }
     void OnTriggerExit(Collider _hit)
     {
         if (_hit.tag == "Platform")
         {
             transform.parent = defaultParant;
         }
     }
     
     void OnCollisionEnter(Collision col)
     {
         if(col.gameObject.tag == "Platform")
         {
             inAir = false;
         }
     }
     
     IEnumerator ShowMessage(string _msg)
     {
         //messageText.SetActive(true);
         //messageText.transform.FindChild("Text").GetComponent<Text>().text = _msg;
         
         yield return new WaitForSeconds(2);
         // messageText.SetActive(false);
     }
     
     void ResetPosToLastCheckpoint()
     {
         //Grab last checkpoint location
         //Change position to last checkpoint position
         if(chkMngr.cache_check_points.Count == 0)
         {
             Application.LoadLevel(0);
             return;
         } else {
             Vector3 grabbedCheckpointPosition = chkMngr.cache_check_points[chkMngr.cache_check_points.Count - 1];
             Debug.Log (grabbedCheckpointPosition);
             transform.position = grabbedCheckpointPosition;
         }
         
     }
 }