Turn off y velocity in 2d Platformer

Hello everyone.

What I want to do is to cut a jump midair by turning off the y velocity midair (like in Hollow Knight). I managed to do that with: rb.velocity = new Vector2(rb.velocity.x, 0f); but my problem is when I cut the jump and I am midair, if I repeat the release jump button process, the whole thing happens again, the character staggers as long as I am releasing the jump button continously. I would like to be able to do that only once when I am off the ground. I am a noob when it comes to coding so I don't really know what to do.

Thank you

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using UnityEngine.Events;
 
 public class PlayerController : MonoBehaviour {
 
     public Animator animator;
 
     private Rigidbody2D rb;
     public float speed;
     private float moveInput;
     public float jumpForce;
 
     private bool isGrounded;
     public Transform feetPos;
     public float checkRadius;
     public LayerMask whatIsGround;
 
     private float jumpTimeCounter;
     public float jumpTime;
     private bool isJumping;
     private bool facingRight = true;
     public float jumpDownForceY = 0;
 
     
     void Start()
     {
         rb = GetComponent<Rigidbody2D>();
 
     }
 
     void Update()
     {
 
         isGrounded = Physics2D.OverlapCircle(feetPos.position, checkRadius, whatIsGround);
 
         if (Input.GetButtonDown("Jump") && rb.velocity.y == 0)
             rb.AddForce(Vector2.up * 700f);
 
         if (Mathf.Abs(moveInput) > 0 && rb.velocity.y == 0)
             animator.SetBool("Running", true);
         else
             animator.SetBool("Running", false);
 
         if (rb.velocity.y == 0)
         {
             animator.SetBool("Jumping", false);
             animator.SetBool("Falling", false);
         }
 
         if (rb.velocity.y > 0.2)
         {
             animator.SetBool("Jumping", true);
         }
             
 
         if (rb.velocity.y < 0)
         {
             animator.SetBool("Jumping", false);
             animator.SetBool("Falling", true);
         }
 
         if (isGrounded == true && Input.GetButtonDown("Jump"))
         {
             isJumping = true;
             
             jumpTimeCounter = jumpTime;
             rb.velocity = Vector2.up * jumpForce;
         }
 
         if (Input.GetButton("Jump") && isJumping == true)
         {
 
             if (jumpTimeCounter > 0){
                 rb.velocity = Vector2.up * jumpForce;
                 jumpTimeCounter -= Time.deltaTime;
             } else {
                 isJumping = false;
             }
 
            
         }
 
         if (Input.GetButtonUp("Jump"))
         {
             isJumping = false;
             rb.velocity = new Vector2(rb.velocity.x, 0f);
 
         }
 
     }
 
     void FixedUpdate()
     {
         moveInput = Input.GetAxisRaw("Horizontal");
         rb.velocity = new Vector2(moveInput * speed, rb.velocity.y);

         Flip(moveInput);
 
     }
 
     private void Flip(float moveInput)
     {
         if (moveInput > 0 && !facingRight || moveInput < 0 && facingRight)
         {
             facingRight = !facingRight;
             Vector3 theScale = transform.localScale;
             theScale.x *= -1;
             transform.localScale = theScale;
         }
 
 
     }
 }