Hi ! Good evening. I am Dr Shareef answering your query. If your symptoms have got worse, this means that the organism giving rise to the sore throat and abscess on tonsil is not sensitive to the antibiotic penicillin. Your headache and the back ache could be due to the persisting fever due to the increasing infection. If I were your doctor, I would go for a throat swab for culture sensitivity test, and while waiting for the report would put you on a broad spectrum antibiotic which might have to be changed as per the sensitivity report. I would also do a clinical examination of your throat to exclude a peritonsilar abscess, in which case I would not hesitate to refer to an ENT specialist who may subject to you to a surgery for draining the abscess, which will cure you. I hope this information would help you in discussing with your family physician/treating doctor in further management of your problem. Please do not hesitate to ask in case of any further doubts. Thanks for choosing health care magic for clearing doubts on your health problems. Wishing you an early recovery. Dr Shareef.