Boxtops has given the sensible answer! However I had a similar situation when I suffered from a severe kidney infection. Antibiotics seemed to clear most of it but I was suffering from stomach cramps and a slight fever and I stopped taking the antibiotics before I had finished the course. As soon as I did this, the stomach cramps stopped and I felt completely fine. If you think that most of the infection has cleared you are probably okay to stop them, but to be on the safe side you could phone NHS direct who are normally pretty helpful with things like this.
Hope you feel better soon, I have also suffered with an ear infection it was horrible so I can sympathise with how bad you must have been feeling!
Sue