Okay, I've been coding a little bit and this is what I got

using UnityEngine;
using System.Collections;

public class UserInterfaceGraphics : MonoBehaviour {


public Rect lifeBarRect;
public Rect lifeBarLabelRect;
public Rect lifeBarBackgroundRect;
public Texture2D lifeBarBackground;
public Texture2D lifeBar;




//private float damage = 10;

private PlayerVitalData PVDScript;
public GameObject PlayerData;


private float LifeBarWidth = 300f;

// Use this for initialization
void Start(){
    instance = this;
    PVDScript = PlayerData.GetComponent("PlayerVitalData") as PlayerVitalData;

}
// Update is called once per frame

public static UserInterfaceGraphics instance;


void OnGUI()
{

    instance.lifeBarRect.width = LifeBarWidth * (PVDScript.life/200);
    instance.lifeBarRect.height = 20;

    instance.lifeBarBackgroundRect.width = LifeBarWidth;
    instance.lifeBarBackgroundRect.height= 20;

    GUI.DrawTexture(lifeBarRect, lifeBar);
    GUI.DrawTexture(lifeBarBackgroundRect, lifeBarBackground);

    GUI.Label(lifeBarLabelRect, "LIFE");



}

}

The Life Bar or Health Bar or whatever now works like wonders. I just got hurried up and made questions too soon, instead of searching before.

I hope it helps anyone down the road.

Use GUI.Box instead. Define the lenght of the box using the amount of life left. You have to call the variables from your health script. You have to make assign your texture in the new style.

For example:

using UnityEngine;
using System.Collections;

public class UserInterfaceGraphics : MonoBehaviour {

public float currentLife;

public GUIStyle : myGUIStyle;

Void OnGUI () {

//For example you have 100 life’s maximum.

GUI.Box(new Rec(10, 10, 0.001 * Screen.width * currentlife,  0.1 * Screen.heigth), “LIFE”, myGUIStyle);

}

}

I hope this is helpfull.