A slice of lime covered in Angosora Bitters works like a champ for me.
just suck, chew, and swallow the lime.
Could your hiccupping be caused by allergies? Could you be allergic to certain foods? Do you remember eating a certain food before it started? Or you could even be allergic to some thing in your house? Maybe dust mites or maybe the perfume your wearing?
Or maybe it's just psychosamatic. Are you stress out about school or a relationship? Have you tried exercising or relaxation techniques.
Just a thought.