How to move a 2D object toward the position it is pointing to?

I have a 2D object i.e as an arrow sprite, it contains three states

1. Rotate.

2. Shoot.

3. Rewind.

The sprite is rotating perfectly as I want it to be i.e like a pendulum. But I am unable to move/shoot it towards the direction its facing.

Following is the code that I had tried.

     switch (ArrowStatus)
             {
                 case "rotate":
                     //Following code is for rotating the Arrow
                     startTime += Time.deltaTime;
                     gameObject.transform.rotation = Quaternion.Lerp(qStart, qEnd, (Mathf.Sin(startTime * speed + Mathf.PI / 2) + 1.0f) / 2.0f);               
                     break;
                 case "shoot":
                     transform.localScale += new Vector3(0, 0.01f, 0);
                     break;
                 case "rewind":
                     break;
 }

I am able to extended scale along the pointing direction but I don't want this. I want to move it towards that direction how can I do that ?