How can I slow down just my character when holding down on the Screen

Hi I need help with this project, I need to slow down a Player but when I implemented the code everything slowed down.

This is the code:

 private Rigidbody2D self;
 public float moveSpeed;
 public float switchTime;
 private bool gameOver = false;
 private int seconds = 0;
 public Text clock;

 void Start()
 {
     self = GetComponent<Rigidbody2D>();
     InvokeRepeating("SwitchDirections", switchTime, switchTime * 2);
     StartCoroutine(Count());
 }

 void UpdateClock()
 {
     seconds += 1;
     clock.text = "Time: " + seconds;
 }

 void SwitchDirections()
 {
     moveSpeed *= -1;
 }

 void FixedUpdate()
 {
     self.velocity = new Vector2(moveSpeed, 0f);
     if (Input.GetMouseButton(0))
     {
         Time.timeScale = 0.5f;
     }
     else
     {
         Time.timeScale = 1f;
     }
 }

 IEnumerator Count()
 {
     while (gameOver == false)
     {
         yield return new WaitForSecondsRealtime(1);
         UpdateClock();
     }
 }