Make Fillamount Match Timer

I have been working on this for days and cannot perfect it! I looked at the unity manual, checked answers, watched tutorials, and tried multiple codes with no success.

I have a timer working for my powerups, but I want a radial fill bar to accompany the timer. I can get the fill bar to decrease, but the fill bar finishes before the timer runs out (around 5-7 seconds before). What am I doing wrong or what do I need to add to make this work? I'd appreciate any help!

Here's my code:

 using UnityEngine;
 using System.Collections;
 using UnityEngine .UI;
 using UnityEngine .SceneManagement ;
 
 public class PowerUpTimer : MonoBehaviour {
 
     public Text timer;
 
     public Color slowDownColor;
     public Color goldToothColor;
     public Color X2Color;
 
     float goldToothTimeAmt;
     float multiplierTimeAmt;
     float slowDownTimeAmt;
 
     public Image goldToothFillImg;
     public Image multiplierFillImg;
     public Image slowDownFillImg;
 
     private float doneTime = 1f;
     private float maxTime;
 
     // Use this for initialization
     void Start () {
 
         goldToothFillImg.enabled = false;
         multiplierFillImg.enabled = false;
         slowDownFillImg.enabled = false;
 
         /*goldToothTimeAmt = GoldToothPowerUp .time ;
         multiplierTimeAmt = Multiplier.time;
         slowDownTimeAmt = TimeChangingPowerUp.time;*/
 
         timer.GetComponent <Text> ();
         timer.enabled = false;
 
     }
     
     // Update is called once per frame
     void Update () {
 
         if (SceneManager.GetActiveScene ().name == "Buck Bite Tyson GameOver Scene") {
 
             timer.enabled = false;
 
         }
 
         if (Multiplier.Active == true) {
 
             //maxTime = 20f;
             multiplierFillImg.enabled = true;
             multiplierFillImg.fillAmount -= 1.0f / Multiplier.time * (Time.deltaTime*0.6f);
             timer.enabled = true;
             Multiplier.time -= Time.deltaTime;
             //multiplierFillImg.fillAmount -= (Time.deltaTime / (Multiplier.time));
             //multiplierFillImg.fillAmount -= (Multiplier.time/Time.deltaTime);
             //multiplierFillImg.fillAmount -= ((doneTime / maxTime)/Time.deltaTime );  
             timer.text = Multiplier.time.ToString ("f0");
             timer.color = X2Color;
 
 
         }
 
         if (Multiplier.time <= 0) {
 
             multiplierFillImg .enabled = false;
             Multiplier.Active = false;
             Multiplier.time = 20f;
             timer.enabled = false;
 
         }
 
         if (GoldToothPowerUp .Active == true) {
 
             //maxTime = 10f;
             goldToothFillImg.enabled = true;
             goldToothFillImg.fillAmount -= 1.0f / GoldToothPowerUp.time * (Time.deltaTime*0.6f);
             timer.enabled = true;
             GoldToothPowerUp .time -= Time.deltaTime;
             //goldToothFillImg.fillAmount -= (Time.deltaTime / (GoldToothPowerUp.time));
             //goldToothFillImg.fillAmount -= (GoldToothPowerUp.time/Time.deltaTime);
             //goldToothFillImg.fillAmount -= ((doneTime / maxTime)/Time.deltaTime );
             timer.text = GoldToothPowerUp .time.ToString ("f0");
             timer.color = goldToothColor ;
 
         }
 
         if (GoldToothPowerUp .time <= 0) {
 
             goldToothFillImg.enabled = false;
             GoldToothPowerUp.Active = false;
             GoldToothPowerUp.time = 10f;
             timer.enabled = false;
 
         }
 
         if (TimeChangingPowerUp .Active == true) {
 
             //maxTime = (20 * Time.deltaTime);
             slowDownFillImg.enabled = true;
             slowDownFillImg.fillAmount -= 1.0f / TimeChangingPowerUp.time * (Time.deltaTime*0.6f);
             timer.enabled = true;
             TimeChangingPowerUp.time  -= (Time.deltaTime/TimeChangingPowerUp.speed) ;
             //slowDownFillImg.fillAmount -= ((Time.deltaTime / TimeChangingPowerUp.speed) / (TimeChangingPowerUp.time));
             //slowDownFillImg.fillAmount -=  (TimeChangingPowerUp.time/Time.deltaTime);
             //slowDownFillImg.fillAmount -= ((doneTime / maxTime)/Time.deltaTime );
             timer.text = TimeChangingPowerUp.time .ToString ("f0");
             timer.color = slowDownColor ;
 
 
         }
 
         if (TimeChangingPowerUp.time <= 0) {
 
             slowDownFillImg.enabled = false;
             TimeChangingPowerUp.Active = false;
             TimeChangingPowerUp.time  = 20f;
             timer.enabled = false;
 
         }
 
     }
 }