Adding force to a rotating wheel using mouse or finger drag.

Apologies for the mess of the code. Not sure why it displays like that. I tried to change it numerous times to no avail. If you look in the comments the code shows neater and the way it's supposed to be.

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class rotation : $$anonymous$$onoBehaviour
 {
 
     private float angle = 0.1f;
 
     Rigidbody rb;
     Vector3 startPos;
     Vector3 endPos;
     float startX;
     float deltaX;
 
     float touchSpeed;
     
     Vector3 Torque;
     float timeStart;
     float timeEnd;
 
     // Use this for initialization
     void Start()
     {
         rb = GetComponent<Rigidbody>();
         //angle1 = transform.eulerAngles.z;
     }
 
     // Update is called once per frame
     void Update()
     {
      
     }
 
     void On$$anonymous$$ouseOver()
     {
 
         Vector3 pos = Camera.main.WorldToScreenPoint(transform.position);
         pos = Input.mousePosition - pos;
         angle = $$anonymous$$athf.Atan2(pos.y, pos.x) * $$anonymous$$athf.Rad2Deg;
         angle -= $$anonymous$$athf.Atan2(transform.right.y, transform.right.x) * $$anonymous$$athf.Rad2Deg;
         //Debug.Log("Angle is " + angle);
     }
 
     void On$$anonymous$$ouseDrag()
     {
         RotateObj();
     }
 
     void RotateObj()
     {
         Vector3 pos = Camera.main.WorldToScreenPoint(transform.position);
         pos = Input.mousePosition - pos;
 
         float ang = $$anonymous$$athf.Atan2(pos.y, pos.x) * $$anonymous$$athf.Rad2Deg - angle;
         transform.rotation = Quaternion.AngleAxis(ang, Vector3.forward);
 //      Debug.Log("Angle is " + ang);
     }
 
     /*void RotateTo(float ang)
     {
         Quaternion newAng = Quaternion.identity;
         newAng.eulerAngles = new Vector3(0, 0, ang);
         transform.rotation = Quaternion.Slerp(transform.rotation, newAng, Time.time * turnSpeed / 30);
         
     }*/
 
     void On$$anonymous$$ouseDown()
     {
         startPos = Input.mousePosition;
         timeStart = Time.time;
         Debug.Log("start is " + startPos);
 
     }
 
     void On$$anonymous$$ouseUp()
     {
         endPos = Input.mousePosition;
         Vector3 deltaPos = endPos - startPos;
         Debug.Log("end is " + endPos);
 
         timeEnd = Time.time;
         touchSpeed = deltaPos.magnitude / (timeEnd - timeStart);
 
         Torque = new Vector3(0, 0, touchSpeed * 1);
         rb.AddTorque(Torque, Force$$anonymous$$ode.Force);
     }
 }