There are many possible causes of throat pain including infection, a foreign body, such as a chicken bone, an ingested irritant or a tumor. This could simply be a strep throat or a viral throat infection; one viral infection in particular, herpes virus can be very painful. But it could also be that you are developing an abscess, such as a boil in or around your tonsil. That you are not even able to swallow saliva is very worrisome, whether because of pain or obstruction.
You should call your doctor immediately and, if you don’t have a doctor or he/she is unavailable, you should proceed to the nearest large hospital emergency room to be examined and treated.