Stupid question but how do you set aside a variable?

Someone please help a newbie out. How do I set aside the value of leanVelocity so it doesn't get affected by forwardVelocity.

Background to my game: The player object "automatically" accelerates after the player inputs a direction to start running to. The player is capable of changing directions. My target "direction change event" goes as follows:

1. Player input change direction

2. Player object's current speed gets deducted by breakForce

3. The player object decelerates speed frame by frame until it reaches the difference of forwardVelocity - breakForce.(or maybe until it halts)

4. (I still have to add this) The player object pauses for half a second before accelerating again

5. player object continues to accelerate in the new direction. "starting" at the leanVelocity.

everytime forwardVelocity changes it affects leanVelocity. I thought using a coroutine will remedy this.

 Update()
 {
 
 ...
 
 if (player_State == "player_Active")
         {
             forwardVelocity += accelRate * Time.deltaTime;
             forwardVelocity = Mathf.Min(forwardVelocity, maxSpd);
             if (player_Direction == "Left")
             {
                 playerRb.velocity = Vector2.right * forwardVelocity;
                 Debug.Log(forwardVelocity);
             }
            else if
 
 ...
 }
 
 void FixedUpdate()
     {
         if (player_State == "player_Slowing")
         {
             StartCoroutine("Decel");
             Invoke("SetActiveState",2);
         }
     }
 
 IEnumerator Decel()
     {
         leanVelocity = forwardVelocity - breakForce;
         while (forwardVelocity > leanVelocity) 
         {
             forwardVelocity += decelRate * Time.deltaTime;
             forwardVelocity = Mathf.Max(forwardVelocity, 0);
             yield return null;
         }
     }

I have to change the whiles condition to ... > 9 for it to "work". 11 is my breakforce, top speed of 20, accelRate of 10 sec, decelRate of 2(?) not sure about this one since I have 2 more sec on Invoke

Sorry in advance if this is noobish :( Please, just point me in the direction on how to reach my goal. Thank you.

whoops! sorry for the dupe, I had to login thought I'd have to rewrite the whole thing.