How would I clamp a balance board? Mathf.clamp does not work!

I've gotten a balance board ALMOST working. However... the mouse controls for it aren't really cooperating right, and I need to clamp them. I tried a Mathf.Clamp and ran into an immediete problem: From 90 degrees pointing up, both directions equal -80 at the points I want to clamp. No negative or positive, just -80, -80.

         Vector3 MouseImpactPoint = GameController.Instance.RawRayPosition;
 
         Vector3 RotateTowards = new Vector3(-(Mathf.Atan2((MouseImpactPoint.x - TiltBed.transform.position.x), (MouseImpactPoint.y - TiltBed.transform.position.y))*Mathf.Rad2Deg - 90), 90, -90);
 
         Debug.Log(RotateTowards);
 
         Quaternion Rot = Quaternion.identity;
 
         Rot.eulerAngles = RotateTowards;
     
         TiltBed.transform.localRotation = Rot;