Unless your sore throat is an actual medical condition that you have researched and have been able to find that the only thing that helps are steroids, then I would consider looking more into a natural route. Steroids are harsh on the body and often cause more damage than they do good.
Keep in mind that your doctor isn't there to hurt you, so if you are unsure just ask more questions. Explain that you are uncertain and ask if there's other ways. Maybe that an refer you to a naturalistic doctor.
Unless your throat is so swollen you can't swallow food or saliva, I agree with you about prednisone being inadvisable. I suggest you gargle with warm salt water (1/2 tsp salt) mixed with about 1/2 tsp of baking soda. See if that doesn't help. Try drinking mint tea.