Clamp rotation of object - Door

Ive tried to find the answer here, but i was not able solve it myself. First of all, im a novice at coding. Trying out Unity for architecture visualization.

Here is what im trying to achive : I use the FPSController to walk around in the scene. I first made a script for opening doors with keydown and animation, with help from a tutorial. Then i figured i wanted to open doors an other way, so i tried makeing a new script :

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class OpenDoorWithScroll : MonoBehaviour
 {
 
     public UnityStandardAssets.Characters.FirstPerson.FirstPersonController controller;
 
     public float RotationSpeed = 4f;
 
     public float MaxRotation = -90f;
     public float MinRotation = 0f;
   
     void Start()
     {
         
     }
 
     void OnMouseDrag()
     {
 
        float rotY = Input.GetAxis("Mouse X") * RotationSpeed * Mathf.Deg2Rad;
         rotY = (Mathf.Clamp(rotY, -45.0F, 45.0F));
         transform.RotateAround(Vector3.up, -rotY);
 
         Debug.Log(rotY);
     }
 }

The rotation works, but i cant clamp it. So it rotates 360 degrees aroud pivot. The Debug returns low numbers, like : 0.135435 and so on. I would like to clamp it at 90 and 0 as the Variables says, and i would like to add that i have to hold down "E", while dragging, not just drag.

I also want to access the FPSController, to turn off the rotation in the MouseLook script when i start dragging the door open. I figured i could turn off X and Y Sensitivity, but somehow i cant access anything on the FPSController, Except "FPSController.SetActive" when FPScontroller is added as public GameObject. If i dont disable rotation here, the cam turns away from the door while im opening it.

Hopefully someone could give me a hand with this.

Thanks.