Slerp Rotating 1 Degree and Limiting All Other Rotation

The title may be sort of confusing, but let me explain.

So I'm building a game in which you can flip your local gravity, not the global, but your gravity and yours alone. I got the gravity flipping correct but having you immediately snap to 180 degrees z is kinda disorienting.

So, I've been trying to make a function that slowly rotates the player. There's obviously something wrong with my slerp function as that's where the actual rotation lies. But, I'm only rotating one degree on the z axis and I cant rotate on any other axis, ie looking around. Here is a my code: //Flip Input if (Input.GetButton("Flip")) gravFlipInput = true; else if (Input.GetButtonUp("Flip")) gravFlipInput = false;

         //Check If Flip Is Possible and If So, Flip
         if (gravFlipInput && !flipping && Grounded())
         {
             flipping = true;
             turning = true;
             DIRECTION = DIRECTION ? false : true;
             flipGrav = DIRECTION ? -1 : 1;
         }
 
         //Check if Flip is Completed
         if (flipping && Grounded())
             flipping = false;
 
         //Actual Flip Process
         if (turning)
             transform.rotation = Quaternion.Slerp(transform.rotation, Quaternion.Euler(new Vector3(transform.rotation.x, transform.rotation.y, transform.rotation.z + 180)), flipInterpolationRatio);
 
         if (turning && (transform.rotation.z == 180 || transform.rotation.z == 0) && flipcancel)
         {
             turning = false;
             flipcancel = false;
         }
 
    //prevents noting starting rotation
     IEnumerator FlipCancel()
     {
         yield return new WaitForSeconds(1);
         flipcancel = true;
     }