collision problems

Basically i have a game with moving objects that if touches my player, player dies. in my death script i have :

// Die by collision void OnCollisionEnter2D(Collision2D other) { Die(); }

and i added a rigidbody and a box collider to my player and a box collider to my moving objects. My problem is that when my player collides with the moving object my player would either tilt to the sides, shake or my moving object will tilt (the player tends to tilt the most). I tried freezing the rotation and position on the rigidbody- constraints. But it didn't work. How to i stop this from happening? can someone please help me. Thank you. Here's my death script:

   using UnityEngine;

   public class death : MonoBehaviour
  {
  // The force which is added when the player jumps
  // This can be changed in the Inspector window
   public Vector2 jumpForce = new Vector2(0, 300);
 
 // Update is called once per frame
 void Update ()
 {
     // Jump
     if (Input.GetKeyUp("space"))
     {
         GetComponent<Rigidbody2D>().velocity = Vector2.zero;
         GetComponent<Rigidbody2D>().AddForce(jumpForce);
     }

 }
 
 // Die by collision
 void OnCollisionEnter2D(Collision2D other)
 {
     Die();
 }
 
 void Die()
 {
     Application.LoadLevel(Application.loadedLevel);
 }

}