MOBILE - FPS Camera Rotation HELP

Hello! I am trying to create a swipe based fps camera. The problem is, the rotation gets all weird.. Like, when the x rotation is 0, the y looks up and down perfect, same vice-versa. I believe that it is because it is rotating using World Space. How could I make it rotate locally? Like, rotate taking in the factor of the other value? Here's the code for better understanding:

 public var cam : Camera;
  
  function Update () {
      if(Input.touchCount > 0) {
 5.         cam.transform.Rotate(-Input.GetTouch(0).deltaPosition.y / 2 * 0.69f, Input.GetTouch(0).deltaPosition.x / 2 * 0.69f, 0);
      }
  }