how can i limit my rope?

I have a rope generated by pure code in a script to do a fishing line, the problem here is when i put the fishing buoy on the rope tip, the rope stretches infinitely and i want the buoy hanging

Thanks in advance

Here is my code:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class hiloCanya : MonoBehaviour
 {
 
     private LineRenderer lineRenderer;
     private List<HiloSegmento> hiloSegmentos = new List<HiloSegmento>();
     private float hiloSegLen = 0.25f;
     private int segmentoLength = 35;
     private float lineWidth = 0.05f;
     [SerializeField] private Transform startPoint;
     [SerializeField] private Transform endPoint;
 
 
     // Use this for initialization
     void Start()
     {
         this.lineRenderer = this.GetComponent<LineRenderer>();
         Vector3 hiloStartPoint = Camera.main.ScreenToWorldPoint(Input.mousePosition);
 
         for (int i = 0; i < segmentoLength; i++)
         {
             this.hiloSegmentos.Add(new HiloSegmento(hiloStartPoint));
             hiloStartPoint.y -= hiloSegLen;
         }
     }
 
     // Update is called once per frame
     void Update()
     {
         this.DrawRope();
     }
 
     private void FixedUpdate()
     {
         this.Simulate();
     }
 
     private void Simulate()
     {
         // SIMULACION
         Vector2 fuerzaGravedad = new Vector2(0f, -1.5f);
 
         for (int i = 1; i < this.segmentoLength; i++)
         {
             HiloSegmento primerSegmento = this.hiloSegmentos[i];
             Vector2 velocidad = primerSegmento.posNow - primerSegmento.posOld;
             primerSegmento.posOld = primerSegmento.posNow;
             primerSegmento.posNow += velocidad;
             primerSegmento.posNow += fuerzaGravedad * Time.fixedDeltaTime;
             this.hiloSegmentos[i] = primerSegmento;
         }
 
         //CONSTRAINTS
         for (int i = 0; i < 50; i++)
         {
             this.ApplyConstraint();
         }
     }
 
     private void ApplyConstraint()
     {
         //Constrant to Mouse
        /* HiloSegmento primerSegmento = this.hiloSegmentos[0];
         primerSegmento.posNow = Camera.main.ScreenToWorldPoint(Input.mousePosition);
         this.hiloSegmentos[0] = primerSegmento; */
 
         //objeto para el principio del hilo
         HiloSegmento primerSegmento = this.hiloSegmentos[0];
         primerSegmento.posNow = this.startPoint.position;
         this.hiloSegmentos[0] = primerSegmento;
 
         //objeto para el final del hilo
         HiloSegmento finalSegmento = this.hiloSegmentos[this.segmentoLength - 1];
         finalSegmento.posNow = this.endPoint.position;
         this.hiloSegmentos[this.segmentoLength - 1] = finalSegmento;
 
         for (int i = 0; i < this.segmentoLength - 1; i++)
         {
             HiloSegmento primerSeg = this.hiloSegmentos[i];
             HiloSegmento segundoSeg = this.hiloSegmentos[i + 1];
 
             float dist = (primerSeg.posNow - segundoSeg.posNow).magnitude;
             float error = Mathf.Abs(dist - this.hiloSegLen);
             Vector2 changeDir = Vector2.zero;
 
             if (dist > hiloSegLen)
             {
                 changeDir = (primerSeg.posNow - segundoSeg.posNow).normalized;
             } else if (dist < hiloSegLen)
             {
                 changeDir = (segundoSeg.posNow - primerSeg.posNow).normalized;
             }
 
             Vector2 changeAmount = changeDir * error;
             if (i != 0)
             {
                 primerSeg.posNow -= changeAmount * 0.5f;
                 this.hiloSegmentos[i] = primerSeg;
                 segundoSeg.posNow += changeAmount * 0.5f;
                 this.hiloSegmentos[i + 1] = segundoSeg;
             }
             else
             {
                 segundoSeg.posNow += changeAmount;
                 this.hiloSegmentos[i + 1] = segundoSeg;
             }
         }
     }
 
     private void DrawRope()
     {
         float lineWidth = this.lineWidth;
         lineRenderer.startWidth = lineWidth;
         lineRenderer.endWidth = lineWidth;
 
         Vector3[] posicionesHilo = new Vector3[this.segmentoLength];
         for (int i = 0; i < this.segmentoLength; i++)
         {
             posicionesHilo[i] = this.hiloSegmentos[i].posNow;
         }
 
         lineRenderer.positionCount = posicionesHilo.Length;
         lineRenderer.SetPositions(posicionesHilo);
     }
 
     public struct HiloSegmento
     {
         public Vector2 posNow;
         public Vector2 posOld;
 
         public HiloSegmento(Vector2 pos)
         {
             this.posNow = pos;
             this.posOld = pos;
         }
     }
 }