How can I reset speed?

I want to reset the ball speed to its original state, because everytime it touches a trigger it gains 1.2 speed, but I'm not being able to reset the ball to its original speed.

My code is like this so far:

   using System.Collections;
   using System.Collections.Generic;
   using UnityEngine;
   
   public class Bola : MonoBehaviour
   {
       public float speed = 2.0f;
       public float maxSpeed = 10.0f;
       private Rigidbody2D rb;
       private Vector3 startPosition;
       public float difficultyMultiplier = 1.2f;
       private AudioSource audioSource;
   
       private float x;
       private float y;
       
       void Start()
       {
           rb = GetComponent<Rigidbody2D>();
   
           startPosition = transform.position;
           Launch();
   
           audioSource = GetComponent<AudioSource>();
   
       }
   
       void Update()
       {
   
           if (this.transform.position.x >= 9f)
           {
               this.transform.position = new Vector3(0f, 0f, 0f);
           }
   
           if (this.transform.position.x <= -9f)
           {
               this.transform.position = new Vector3(0f, 0f, 0f);
           }
       }
   
   
       private void Launch()
       {
           if (Random.Range(0, 2) == 0)
           {
               x = -1;
           }
           else
           {
               x = 1;
           }
   
           if (Random.Range(0, 2) == 0)
           {
               y = -1;
           }
           else
           {
               y = 1;
           }
   
           rb.velocity = new Vector2(speed * x, speed * y);
       }
   
       private void OnCollisionEnter2D(Collision2D collider)
       {
           audioSource.Play();
       }
   
       public void Reset()
       {
           transform.position = startPosition;
           Launch();
       }
   
       private void OnTriggerEnter2D(Collider2D collision)
       {
           if (collision.gameObject.tag == "Raquete")
           {
               if (difficultyMultiplier * speed < maxSpeed)
               {
                   speed *= difficultyMultiplier;
                   rb.velocity *= difficultyMultiplier;
               }
           }
       }
   }

If anyone could help me, I would be very grateful!