I spill my semen in my dreams every night, so what should I do to stop it?
I suspect that you're exaggerating a bit. However, what is happening is that your body is producing more semen than it can store so it is getting rid of the excess through wet dreams. Since the amount of semen produced increases when you are aroused, one thing you can do is avoid looking at or thinking of things related to sex. I know it is a tall order when you are a teenager since it seems that almost everything has a sexual connotation to the teenage mind, but by limiting your exposure, it will allow your body to slow down.