Button input getting stuck

So I use Buttons to control my player from the left to the right. When he collides with a Spike the character dies and the input gets deactivated until he respawns after 2 seconds. My problem is now that after the respawn the player character keeps the speed he had when colliding with the spike.

 using UnityEngine;
 using System.Collections;
 using UnityEngine.EventSystems;
 
 public class PlayerMovement : MonoBehaviour {
 
     // speed
     public float speed = 30;
 
     float hInput = 0;
 
     Transform myTrans;
     Rigidbody2D myBody;
 
 
     // save the checkpoint
     Transform check;
 
     // check if the player is not dead
     public bool PlayerDead = false;
 
     void Start()
     {
         myBody = this.GetComponent<Rigidbody2D>();
         myTrans = this.transform;
     }
 
     void OnTriggerEnter2D(Collider2D co)
     {
         // checkpoint?
         if (co.gameObject.tag == "Checkpoint")
             check = co.transform;
             
     }
     
     // Update is called once per frame
     void Update () {    
         //Horizontal Movement
         //float h = Input.GetAxisRaw ("Horizontal");
         //GetComponent<Rigidbody2D> ().velocity = Vector2.right * h * speed;
 
 
         
         // Gravity Changes
         if (Input.GetKeyDown (KeyCode.Space)) {
             GetComponent<Rigidbody2D> ().gravityScale *= -1;
             transform.Rotate (0, 180, 180);
         }
 
     }
 
     void Move(float horizontalInput)
     {
         // the move command which is applied to the player
         // 1. new vector
         // 2. what the vector is
         // 3. apply to the players body
         Vector2 moveVel = myBody.velocity;
         moveVel.x = horizontalInput * speed;
         myBody.velocity = moveVel;
     }
 
 
     void FixedUpdate()
     {
         if (PlayerDead == false) {
             // just calling the player to move every physics update
             Move (hInput);
         } 
         
     }
 
     
     public void StartMoving(float horizontalInput)
     {
 
         if (PlayerDead == false) {
             // the command for the button to move
             hInput = horizontalInput;
         }
     }
 
     public void ButtonGravity()
     {
         if (PlayerDead == false) 
             {
                 GetComponent<Rigidbody2D> ().gravityScale *= -1;
                 transform.Rotate (0, 180, 180);
             }
     }    
 
     IEnumerator OnCollisionEnter2D(Collision2D co) {
         // Collided with a Collidethingy?
         if (co.gameObject.tag == "Spike") {
             // Reset Rotation, Gravity, Velocity and go to last Checkpoint
             PlayerDead = true;
             yield return new WaitForSeconds(2);
             transform.rotation = Quaternion.identity;
             GetComponent<Rigidbody2D>().gravityScale = Mathf.Abs(GetComponent<Rigidbody2D>().gravityScale);
             GetComponent<Rigidbody2D>().velocity = Vector2.zero;
             transform.position = check.position;
             PlayerDead = false;
 
 
         }
     }
 
 
 }