Line Renderering Issue

Hello, I am trying to create a game where the user will be able to use their mouse to draw lines anywhere on the screen. I also have objects falling from above with the idea that if an object hits an object the object gets destroyed. I have used a line renderer to create a line and I thought I'd use ray casting to detect an object being hit. This doesn't seem to be working like I want it to though. Where am I going wrong?

using UnityEngine; using System.Collections;

public class FollowMouse : MonoBehaviour {

 private LineRenderer LR;
 public bool drawLine = false;
 public Vector2 origin;
 public Vector2 destination;
 GameObject camera;

 void Start () {
     // Grab Line Render object
     LR = GetComponent<LineRenderer>();
     // Width of line.
     LR.SetWidth(.15f,.15f);
     // Cache Camera
     camera  = GameObject.FindGameObjectWithTag("MainCamera");
 }
 
 // Update is called once per frame
 void Update () {
     // If the left button is pressed down
     if(Input.GetMouseButtonDown(0) && !drawLine){
         // Capture the mouse origin
         Vector3 mouseOrigin = camera.GetComponent<Camera>().ScreenToWorldPoint(Input.mousePosition);
         // place mouse origin in a vector.
         origin = new Vector2(mouseOrigin.x,mouseOrigin.y);
         // Don't capture origin again.
         drawLine = !drawLine;
         // MAke the line visible.
         LR.enabled = true;
     }
     // Draw the line dynamically
     if(drawLine){
         DrawLine();
     }
     // If user lifts button then erase line.
     if(Input.GetMouseButtonUp(0)){
         //Let the user draw a new line.
         drawLine = !drawLine;
         // Line is erased
         LR.enabled = false;
     }
 }

 void DrawLine(){
     // Capture where mouse is dragged to
     Vector3 mousepos= camera.GetComponent<Camera>().ScreenToWorldPoint(Input.mousePosition);
     destination = new Vector2(mousepos.x,mousepos.y);
     // Start line at click
     LR.SetPosition(0,origin);
     // End line at mouse position
     LR.SetPosition(1,destination);

     RaycastHit2D ray = Physics2D.Raycast(origin,destination);

     if(ray != null){
         Debug.Log(ray.ToString);
     }

 }

}