Rheumatic fever is caused by the same bacteria that causes strep throat. There can be significant complications if rheumatic fever is not treated. If you really think you have rheumatic fever, you need to see a doctor.
That being said, most sore throats are usually viral in nature. Symptoms are pretty common sense, sore throat, redness, irritation, maybe hoarseness etc. Treat the symptoms, i.e. tylenol/motrin for pain, warm salt water gargles for the irritation of the throat, hard candy/throat lozenges to soothe the throat. If that doesn't resolve the symptoms in 2-3 days, or they get worse, see your physician.