Try gargling with apple cider vinegar or warm salt water several times a day to ease your sore throat...this always seems to help me.
If the OJ is hurting one thing I have done after a fast is to drink veggie broth with miso. I agree with the other post that your sore throat is a sign of remaining toxicity that your body was trying to purge.
Just be careful about what you are now putting into you clean colon. Animals fast when they are not feeling well. If you don't feel well you could follow their lead and just do the broth a few days. When I make veggie broth I use all my favorites plus with a sore throat I would include a lot of ginger, garlic & onion....just boil & drain away the veggies add miso or not.