jump and check ground problem!

How do I solve this problem?

When a player is placed in a corner , player can't jump!!!

my script is:

 using UnityEngine;
 using System.Collections;
 
 public class asli : MonoBehaviour {
     public Animator anim;
     public bool jump = false;                // Condition for whether the player should jump.
     public float jumpForce = 1000f;            // Amount of force added when the player jumps.
     private Transform groundCheck;            // A position marking where to check if the player is grounded.
     private bool grounded = false;            // Whether or not the player is grounded.
     public float speed=2;
 
     void Start () {
         anim=gameObject.GetComponent<Animator>();
         groundCheck = transform.Find("groundCheck");
     }
     
     // Update is called once per frame
     void Update () {
 
         grounded = Physics2D.Linecast(transform.position, groundCheck.position, 1 << LayerMask.NameToLayer("Ground"));  
         if(grounded==true){    anim.SetBool("paresh",false);}else{anim.SetBool("paresh",true);}
         if(Input.GetButtonDown("Jump") && grounded)
             jump = true;
     }
     void FixedUpdate ()
     {
 
         anim.SetFloat("M",Mathf.Abs(Input.GetAxisRaw("Horizontal")));
         if(Input.GetAxisRaw("Horizontal")>0)
         {
             
             transform.Translate(Vector3.right*speed*Time.deltaTime);
             transform.eulerAngles=new Vector2(0,0);
         }    
         if(Input.GetAxisRaw("Horizontal")<0)
         {
             
             transform.Translate(Vector3.right*speed*Time.deltaTime);
             transform.eulerAngles=new Vector2(0,180);
         }
 
         // If the player should jump...
         if(jump)
         {
     
 
             // Add a vertical force to the player.
             rigidbody2D.AddForce(new Vector2(0f, jumpForce));
         
             // Make sure the player can't jump again until the jump conditions from Update are satisfied.
             jump = false;
         }
     }
     void OnCollisionExit2D(Collision2D coll) {
         if (coll.gameObject.tag == "ground")
             grounded=true;
         
     }
 }