Health Bar Issues

What I would do is use GUI.Box. Then feed the health value into the length and/or width of the rectangle (scale as needed). You can use a custom texture by passing in a GUIContent Object with your health bar texture on it. You can also pass your health as a string to have it displayed on the box.

This is what I'm using for my game's health bar, and I think it is all you need for yours.

Hope this helped

It can make health bar easily...

 var yourHealth = 100.0;
 var yourMaxHealth = 100.0;

 function Start ()
 {
     yourHealth = yourMaxHealth;
 }

 function OnGUI ()
 {
     GUI.HorizontalScrollbar(Rect (0,40,300,20), 0, yourHealth,0, yourMaxHealth);
 }