Get sprite size and position

I need some help to find a way to get the sprite's size.

I try to put a texture on my sprite like this :

GUI.DrawTexture(new Rect(mySpriteBotLeftX, mySpriteBotLeftY, mySpriteWidth, mySpriteHeight), myTexture);

In my script I use a RequireComponent to get a SpriteRenderer. In scene mode I would like to be able to change the size of this sprite to easily get a rect of the size that I need. I tried something like this but it didn't work :

sprite_size = GetComponent().sprite.rect.size; local_sprite_size = sprite_size / GetComponent<SpriteRenderer>().sprite.pixelsPerUnit; world_size = local_sprite_size; world_size.x *= transform.lossyScale.x; world_size.y *= transform.lossyScale.y; screen_size = 0.5f * world_size / Camera.main.orthographicSize; screen_size.y *= Camera.main.aspect; screen_size.x *= Camera.main.aspect; in_pixels = new Vector3(screen_size.x * Camera.main.pixelWidth, screen_size.y * Camera.main.pixelHeight, 0) * 0.5f;

Any ideas to help me with this ?