Basic 2d movement problem: glitching in terrain

Hello, I have a problem. I'm making a 2d platformer, but when I move I glitch into a wall if I stand next to it and try to move. My player is, like my walls, just a cube. How do I solve this problem, so my player doesn't glitch into walls. So he just stays still, even if I try do move him into the wall?Thank you, -Nelis

 #pragma strict
 
 
 //Variables
 var MovementSpeed : float = 0.1;
 var JumpHeight : int = 350;
 var SecsBetweenJumps : float = 1.5;
 
 //Booleans
 var CanJump : boolean = true;
 
 function Start () {
 
 }
 
 function Update () {
     if(Input.GetKey(KeyCode.LeftArrow)){
         transform.Translate(Vector3.left * MovementSpeed);
     }
     if(Input.GetKey(KeyCode.RightArrow)){
         transform.Translate(Vector3.right * MovementSpeed);
     }
     if(Input.GetKeyDown(KeyCode.UpArrow) && CanJump){
         Jump();
     }
 }
 
 function Jump(){
     CanJump = false;
     rigidbody2D.AddForce(Vector3.up * JumpHeight);
     yield WaitForSeconds(SecsBetweenJumps);
     CanJump = true;
 }