Firing to a mouse position

Hi, I sort of have the basics to this, but in the instantiate part, I don't know how to include the mouse position, essentially the debug.drawline will go to the mouse position, but I want to have the instantiate go from firePointPosition to mousePosition.

 using UnityEngine;
 using System.Collections;


 public class Attack : MonoBehaviour {

 //public float fireRate = 0;
 private bool canAttack;
 public float damage = 10;
 public float fireDistance = 100;
 public LayerMask whatToHit;

 private float timeToFire = 0;
 private Transform firePoint;
 public GameObject projectile;
 // Use this for initialization
 void Start () {
 
     firePoint = transform.FindChild("FirePoint");

     if (firePoint == null) {
         Debug.LogError ("No Firepoint");
     }

     canAttack = true;

 }
 
 // Update is called once per frame
 void Update () {
     //Shoot ();
     if (Input.GetButtonDown("Fire1") || Input.GetMouseButton(0)) {
             //Shoot ();
         //StartCoroutine (Shoot);
         StartCoroutine ("Shoot");
     }
 }

 IEnumerator Shoot(){
     //Debug.Log ("pow pow");
     if (canAttack == true){
         canAttack = false;
         //shooting to the mousepositions x and y
         Vector2 mousePosition = new Vector2(Camera.main.ScreenToWorldPoint(Input.mousePosition).x, Camera.main.ScreenToWorldPoint(Input.mousePosition).y);
         Vector2 firePointPosition = new Vector2 (firePoint.position.x, firePoint.position.y);
         RaycastHit2D hit = Physics2D.Raycast (firePointPosition, mousePosition - firePointPosition, fireDistance, whatToHit);

         Quaternion q = Quaternion.FromToRotation (Vector3.up, (mousePosition - firePointPosition) * fireDistance);
         var shoot = Instantiate (projectile, firePointPosition, q);
         yield return new WaitForSeconds (0.25f);
         canAttack = true;
         Debug.DrawLine (firePointPosition, (mousePosition - firePointPosition) * fireDistance, Color.red);
         //        if (hit.collider != null) {
         //            Debug.DrawLine (firePointPosition, hit.point, Color.blue);
         //        }
     }


 }

}