Backsliding like a baws

Hella people !

Im't actually trying to tweak a bit the walking script of the tutorial for 2d games. Here's the thing : using UnityEngine; using System.Collections;

 public class CharacterControllerScript : MonoBehaviour
 {
     public float maxSpeed = 10f;
     bool facingRight = true;
 
     Animator anim;
     
     // Use this for initialization
     void Start ()
     {
         anim = GetComponent<Animator> ();
     }
     
     // Update is called once per frame
     void FixedUpdate () 
     {
         float move = Input.GetAxis ("Horizontal");
         anim.SetFloat ("Speed", Mathf.Abs (move));
         rigidbody2D.velocity = new Vector2 (Mathf.Sign(move) * maxSpeed, rigidbody2D.velocity.y);
         if (move > 0 && !facingRight)
             Flip ();
         else if (move < 0 && facingRight)
             Flip ();
     }
 
     void Flip ()
     {
         facingRight = !facingRight;
         Vector3 theScale = transform.localScale;
         theScale.x *= -1;
         transform.localScale = theScale;
     }
 }

As you can see, I've replaced the common "move maxSpeed" by "Mathf.Sign(move) maxSpeed". The purpose is to prevent speed variations with a joystick, so the gameplay's still the same with a keyboard and a gamepad. Also I've added kind of a "startup" and "recovery" frames, using the "curve" fonction and modulating the maxSpeed during "start walking" and "return to idle" animations.

Now here's the problem :

When the char is going left and I instantly stop to press the left key, the char is sliding backward. I've tried to test this with a keyboard and the reaction is the same. I've tried to suppress the "recovery" frames and it worsen the problem ; turning the char into an unstoppable backslide masta'.

Edit: the problem comes from the fact that "mathf.Sign()" can never return the 0 value, since it is returning 1 as for 0 or positive numbers, so if I keep suing this function I need to find a way to return 0 when the player doesn't press anything.

So if someone has a solution to keep the "no variation in speed" gameplay style, without using a clunky "if", and keeping the "startup" and "recovery" frames : I'll thank him greatly. ^^