Launching character up and stopping on same horizontal position

Hello everyone.

I made a game where the player has the ability to click on the enemy character and drag them any direction. When the player lets go, I calculate the direction and a force and apply it to the enemy, thus launching them in that direction. Gravity is then added to the rigidbody of the enemy causing the enemy to go up and then eventually come back down. The problem I am having is that I want the enemy to stop at the same horizontal axis where he was when he was first clicked on. I am having some issues getting the player to stop where he first left. Does any one have any ideas how I can do this?

I have attached my code and a picture explaining below. If their is any way i can attach video or get video to you please let me know!

 using UnityEngine;
 using System.Collections;
 
 public class UserInput : MonoBehaviour {
 
     public EnemyMovment enemyMovment;
     const float LAUNCH_SPEED = 3000;
     //store gameObject reference
     public Object BottomWall;
     GameObject enemyBottomWall;
     public Transform castle;
     public GameObject Enemy_Obj;
     public Rigidbody2D rigidbody;
     public float movesSpeed = 10;
     //public Camera camera;
 
     //holds mouse position
     Vector3 mouseLastPosition;
     Vector3 mouseCurrentPosition;
     Vector3 mouseDiffrenceInPosition;
     Vector3 skeletonXPosition;
 
     int counter;
     Vector2 mMouseDownPos;
     Vector2 mMouseUpPos;
     public float speed;
     public float throwLeftOrRight;  // positive throws right and left throws blank
     public float throwUpOrDown;     // positive throws up and negative throws down
     public Transform skeleton;              //castle target
     public SpriteRenderer spriteRenderer; //sprite render refrence
     private Animator animator;            //animator refrence
     public Sprite Idle;
 
     // Use this for initialization
     void Start () 
     { 
 
         //gets animator for animator refrence
         animator = GetComponent<Animator>();
         rigidbody = GetComponent<Rigidbody2D>();
     }
 
     // Update is called once per frame
     void Update () 
     {
 
     
 
         //statment that will save old position every other time to increase distances for projection calculations
         if (counter % 2 == 0) 
         {
             //Saves last mouse poition
             mouseLastPosition = mouseCurrentPosition;
         }
         //Gets new mouse position
         mouseCurrentPosition = new Vector3 (Input.mousePosition.x, Input.mousePosition.y, 10);
 
         //increments counter for if statment
         counter++;
 
         //function that checks when the mouse button is released. It will performe the actions below when the mouse is released
         if (Input.GetMouseButtonUp (0))
         {
 
             //Ingnores collision between wall layer and building layer
             //Allows enemy to pass threw buildings when picked up
             Physics2D.IgnoreLayerCollision(8, 9,true);
         
             //Calculates the diffrence in position between last mouse position and current
             mouseDiffrenceInPosition = mouseCurrentPosition - mouseLastPosition;
 
             //calculates which way to throw character based on mouse position diffrence * launch speed
             throwLeftOrRight = (mouseDiffrenceInPosition.x / 2)* LAUNCH_SPEED;
             throwUpOrDown = (mouseDiffrenceInPosition.y / 2) * LAUNCH_SPEED;
 
             //Throws enemy in direction calculated by mouse position
             rigidbody.AddForce(new Vector2(throwLeftOrRight, throwUpOrDown));
 
             //adds gravity to enemy
             rigidbody.gravityScale = 16;
         }
 
 
     }
 
     //function that detects if the enemy has the mouse over them
     public void OnMouseOver(){
 
         //If statment that detects if the enemy has been clicked on
         if (Input.GetMouseButtonDown(0)) {
 
 
             Enemy_Obj.layer = 8;               //sets enemy layer to wall layer
             spriteRenderer.sprite = Idle;      //changes sprite to idle sprite
             animator.Stop();                   //stops animation
             enemyMovment.stopWalking = true;   //makes player stop walking
 
             //Gets the x position of the enemy
             skeletonXPosition = transform.position;
             //sets the y and z to zero
             skeletonXPosition.y = 0;
             skeletonXPosition.z = 0;
 
         }
     }
 
     //drags the enemy with the mouse
     public void OnMouseDrag()
     {
         //moves skeleton to mouse position
         Vector3 mousePosition = new Vector3 (Input.mousePosition.x, Input.mousePosition.y, 10);
         Vector3 objectPosition = Camera.main.ScreenToWorldPoint (mousePosition);
 
         transform.position = objectPosition;
 
     }
 }

[1]: /storage/temp/81119-unity-example.png