I lost my voice yesterday afternoon and now am getting a sore throat should i go to the doctor?

Not necessarily: It appears that you are developing laryngitis (voice box inflammation). In most cases it is caused by a virus and is a self limited disease requiring no major treatment or a visit to doctor. Fever, especially past 3 days, symptoms of choking, drooling, stridor (whistling while taking a breath), shortness of breath must be evaluated promptly as they may be a sign of a life threatening disease.

Listen to your body: When you lose your voice, your first instinct should be to rest it. That means no whispering, shouting or talking on the cellphone in public as these stress the voice. If this is sudden, rest and treat the (likely) oncoming cold/flu with supportive measures. If the change lasts more than 10 days or you get better but the voice is still gone, go see a voice specialist- we're here to help you!