Camera rotate using two fingers - mobile c#

I have a script where i use the positions of two fingers, and their deltapositions, and then calculate angles using vector2.angle, and if it increases then rotate camera right, and decreases i rotate left. i got that part to work. but how do i accommodate for when the two fingers pass each other (and are on the same line when create angles relative to 0,0)? When they cross each other, the angle increases (and camera rotate in other direction).

here is my code snippet: (in update method attached to camera (which is parented to invis empty gameobject to be able to rotate around)

 currentAngleBetweenTouches = Vector2.Angle(Input.GetTouch(0).position, Input.GetTouch(1).position);
 
 prevAngleBetweenTouches = Vector2.Angle((Input.GetTouch(0).position - Input.GetTouch(0).deltaPosition), (Input.GetTouch(1).position - Input.GetTouch(1).deltaPosition));
             
 if ((currentAngleBetweenTouches - prevAngleBetweenTouches) - 0.25 > 0) //DeltaAngle posative, rotating clockwise
             {
                 mainCamera.transform.parent.transform.Rotate(new Vector3(0.0F,0.0F,-5.0F)); //why 5? How do i accommodate for actual angle ?
 else if ((currentAngleBetweenTouches - prevAngleBetweenTouches) + 0.25 < 0) //DeltaAngle negative, rotating counter-clockwise
                 {
                     mainCamera.transform.parent.transform.Rotate(new Vector3(0.0F,0.0F,5.0F));
                 }