Character movement is not working??

Questions & Answers
1

My character is supposed to slow down when the button is held down I have spent days trying to fix it can someone please help
using System.Collections;
using System.Collections.Generic;
using UnityEngine.UI;
using UnityEngine;

public class SlowDownScript : MonoBehaviour
{

private Rigidbody2D self;
public float moveSpeed;
public float switchTime;
public float changeSpeed;
private bool gameOver = false;
public 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 Update()
    {
    self.velocity = new Vector2(moveSpeed, 1f);
    if (Input.GetMouseButtonDown(0))
      {
         self.velocity = new Vector2(moveSpeed, 0.5f);
      }
    }

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

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

}

}

2

You are using Input.GetMouseButtonDown(int). This triggers the event only at the moment you press on your mouse button. I think replacing it by Input.GetMouseButton(int) will work.