If it's exactly the opposite way, it's because it may be facing 'left' when you made the Sprite. Note: All sprites have default direction facing right.
One way to fix would be to Edit the Sprite, Flip the image horizontally.
In the Event Sheet, instead of pointing towards an object. Set Angle and write:
angle(sprite.X, sprite.Y, mouse.X, mouse.Y) + 180
That should solve it.