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You sure have tonsillitis. Now considering the test results are negative, it is most likely a viral infection. But we cannot be sure, and so you should take an entire course of antibiotics. You have said you are taking Amoxicillin. Good. Next, the bump and the enlarged tonsil with redness and stones all signify some active infection now. There is pus production which is clogging the tonsillar pits (we call it crypts, though). These pits are normal, but when they get clogged with stones and pus, it becomes a problem and shows symptoms. I saw the picture (attachment removed to protect the patient's identity), they do not look cancerous. In addition to the antibiotic, I would suggest some anti-inflammatory painkiller medicines like Tylenol (Acetaminophen) and Brufen (Ibuprofen) and some antiallergics like Desloratadine or Cetirizine. Do warm saline or medicated gargles a few times daily. No smoking. Do not get exposed to dust and cold air. Keep yourself warm and hydrated. Avoid spicy, oily foods and carbonated drinks. Do revert if you need any more help. Happy to be helping you.