Game freezing after adding game objects with OnMouseDown () to control movement of character rather than mouse keys

In my game i want it to be eventually made controllable by touch for mobile devices. So first i plan to make everything controllable by mouse then just switch it over. So instead of moving my player with arrow keys to dodge instantiated obstacles i was going to click an object which would work the same as pressing a mouse key. After struggling with event systems and UI buttons, listeners, etc, i decided to create a game object with code which would happen when it was clicked. Hence the code below.

For left object

 using UnityEngine;
 using System.Collections;
 
 public class Leftt : MonoBehaviour {
     public new Vector3 position;
     // Use this for initialization
     void Start () {
     
     }
     
     // Update is called once per frame
     void Update () {
     
     }
 
     void OnMouseDown () {
         Debug.Log ("Left");
 
         GameObject player = GameObject.Find("Player");
         Movement playerScript = player.GetComponent<Movement>();
         position = playerScript.position;
         
         if (position == new Vector3(0,1,-40))
         {
             playerScript.transform.position = new Vector3(-10,1,-40);
         }
         
         if (position == new Vector3(10,1,-40))
         {
             playerScript.transform.position = new Vector3(0,1,-40);    
         }
     }
 }

For right object

 using UnityEngine;
 using System.Collections;
 
 public class Rightt : MonoBehaviour {
     public new Vector3 position;
     // Use this for initialization
     void Start () {
     
     }
     
     // Update is called once per frame
     void Update () {
     
     }
 
     void OnMouseDown () {
         Debug.Log ("Right");
 
         GameObject player = GameObject.Find("Player");
         Movement playerScript = player.GetComponent<Movement>();
         position = playerScript.position;
 
         if (position == new Vector3(0,1,-40))
         {
             playerScript.transform.position = new Vector3(10,1,-40);
         }
         
         if (transform.position == new Vector3(-10,1,-40))
         {
             playerScript.transform.position = new Vector3(0,1,-40);
         }
     }
 }

I then played it and at first the code was working and i just clicked the object like pressing left and right arrow keys but then the instantiated objects (obstacles to dodge) came and the controls stopped. I guess freezing up because of spikes in CPU of sorts which seemed to happen in the profiler. I know this has to be because of my change of controls because it worked before with arrow keys. But 'why would that make a difference and what can i do to solve it?' i wandered and now i am asking you.

Thank you for any answers this is the last thing i need to do in completing my game which i have spent a long time on. Answers/ help much needed. :-)