I'm not sure if I understood correctly. I've added an instance variable that checks if you have the coin or not. So if you die and don't have the coin, nothing happens to the score, and if you die and you have the coin, subtract 1 to the score.
Tell me if this is not what you wanted and try to explain it again.
By the way, you are using too many sprites and the system has to check a lot of collisions which is not good for performance. Instead of using a lot of small sprites, use the Tiled Background object, that way the system will only have to check very few objects.