How can I improve 2D Jump? because it's sluggish

So, I made a 2D Game with separated Jump and Walk Scripts for my HTML5 Game which is a 2D Platformer, but it has a sluggish Jump. You can tell it especially in Test Levels 2 and 4, where the Camera moves according to the Player Movement. How can I improve this Code, so the Player Jumps immidiately rather than Floating a few Centimeters in the Air before Jumping?

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class PlayerJumpV3 : MonoBehaviour {

 public Rigidbody2D rb2d;

 public float JumpForce;

 public float MaxTime;
 private float CurrentTime;

 private bool Grounded;
 public bool CanHoldJump;

 // Use this for initialization
 void Start () {

     rb2d = GetComponent<Rigidbody2D>();

     JumpForce = 30;

     MaxTime = 0.25f;
     CurrentTime = MaxTime;

     Grounded = true;
     CanHoldJump = true;

 }

 // Update is called once per frame
 void Update () {

     if (CanHoldJump == true)
     {
         if (CurrentTime >= 0)
         {
             rb2d.AddForce (new Vector2 (0, Input.GetAxis ("Jump")) * JumpForce * Time.deltaTime, ForceMode2D.Impulse);
             CurrentTime -= Time.deltaTime;
         }
     }
     else if (Grounded == false)
     {
         CanHoldJump = false;
     }

     if (Grounded == true)
     {
         CurrentTime = MaxTime;
     }

 }

 private void OnCollisionStay2D(Collision2D collision)
 {
     if (collision.gameObject.tag == "Ground")
     {
         Grounded = true;
         CanHoldJump = true;
     }
 }

 private void OnCollisionExit2D(Collision2D collision)
 {
     if (collision.gameObject.tag == "Ground")
     {
         Grounded = false;
     }
 }

}