It looks like you have a viral infection i.e herpes.no need to take any medications just try to avoid contact with it it will resolve in one week to ten days

According to the picture provided, it seems like an Herpes infection. Herpes simplex is a viral disease caused by the herpes simplex virus. Infections are categorized based on the part of the body infected. Oral herpes involves the face or mouth. It may result in small blisters in groups often called cold sores or fever blisters or may just cause a sore throat. These typically heal over two to four weeks. Tingling or shooting pains may occur before the blisters appear. Herpes cycles between periods of active disease followed by periods without symptoms. The first episode is often more severe and may be associated with fever, muscle pains, swollen lymph nodes and headaches. Over time, episodes of active disease decrease in frequency and severity. Symptoms: Blisters that break open and form small ulcers, fever, swollen lymph nodes Duration: 2–4 weeks Causes: Herpes simplex virus spread by direct contact Risk factors: Decreased immune function, stress, sunlight, lack of sleep Dental Galaxy, Pune. http://goo.gl/Beq3qB

This is probably what is called a cold soar, may or may not be associated with symptoms like fever. It is most often due to reactivation of an old herpez virus infection. It Should go within 2 weeks, if you have no other medical conditions. In the meanwhile try cold and heat to see which helps you. If the discomfort is too severe , there are prescription medication available .