Since your symptoms started with a cold, they are likely caused by a virus. Antibiotics only treat bacterial infections and will not work against viruses. For immediate relief from the fever and earache, you can take over-the-counter pain relievers like paracetamol or ibuprofen. Resting and staying hydrated will also help your recovery. Please consult a doctor to examine your ear; they can determine if a secondary bacterial infection has developed, which might require a prescription antibiotic like amoxicillin. Seek medical care promptly if you experience severe pain, dizziness, or a worsening fever.