Transform.Translate | Self | World

Hi,

I am working on a VR application with Google Cardboard, where in I am trying to simulate movement on click of the magnetic button.

My question is related to the movement, where in I am trying to move the user with Head Bobbing to simulate realistic walking. Following is the code snippet:

 public class ControlCamera : MonoBehaviour {
 
     float timer = 0.0f; 
     public float bobbingSpeed = 0.18f; 
     public float bobbingAmount = 0.2f; 
     public float midpoint = 1.0f; 
     public float horizontal = 10.0f; 
     public float vertical = 10.0f; 
     
     // Update is called once per frame
     void Update () 
     {
         float waveslice = 0.0f; 
 
         if (Sensors.isMove) 
         {
             // transform.Translate (Vector3.forward * Time.deltaTime);
 
             if (Mathf.Abs(horizontal) == 0 && Mathf.Abs(vertical) == 0) 
             { 
                 timer = 0.0f; 
             } 
             
             else 
             { 
                 waveslice = Mathf.Sin(timer); 
                 timer = timer + bobbingSpeed; 
                 
                 if (timer > Mathf.PI * 2) 
                 { 
                     timer = timer - (Mathf.PI * 2); 
                 } 
             } 
             
             if (waveslice != 0) 
             { 
                 float translateChange = waveslice * bobbingAmount; 
                 float totalAxes = Mathf.Abs(horizontal) + Mathf.Abs(vertical); 
                 totalAxes = (float) Mathf.Clamp (totalAxes, 0.0f, 1.0f); 
                 translateChange = totalAxes * translateChange; 
                 
                 transform.Translate(Vector3.forward * Time.deltaTime);
                 transform.Translate(new Vector3(0.0f, (midpoint + translateChange), 0.0f), Space.World);
             } 
             
             else 
             { 
                 transform.Translate(Vector3.forward * Time.deltaTime);
                 transform.Translate(new Vector3(0.0f, (midpoint + translateChange), 0.0f), Space.World);
             }
         }
     }
 }

I am trying to integrate the forward translate with the head-bobbing in the above code, one translate is Space.Self (forward motion) whereas the other translate is Space.World (head-bobbing).

Whenever I am trying to do both the things in separate lines of code only the head-bobbing is done whereas the forward translate doesn't happen.

Link to head bobbing

Any help is appreciated, thanks in advance!