Since you describe your respiratory infection as severe, it is crucial that you see a doctor immediately for a proper diagnosis, as you may require prescription-strength medications. For temporary relief of your headache and any fever, you can take over-the-counter pain relievers like acetaminophen or ibuprofen, provided you have no contraindications. Do not take leftover antibiotics, as they may not target your specific infection. Please rest, stay well-hydrated, and seek emergency medical care immediately if you experience shortness of breath, chest pain, or a persistently high fever.

For temporary relief of your tooth pain and headache, you can take over-the-counter pain relievers like Ibuprofen (400 mg) or Acetaminophen (500 mg) every 4 to 6 hours, following package directions. However, since these symptoms have persisted for a week, they likely indicate an underlying dental infection, abscess, or sinus issue. Painkillers will only temporarily mask the pain; they cannot cure an infection. You must see a dentist promptly for a proper diagnosis and treatment (which may require prescription antibiotics or dental work). If you develop facial swelling, fever, or difficulty breathing, please seek emergency medical attention immediately.

Your symptoms of pain behind the knee radiating down your leg could indicate sciatica (a pinched nerve in your back), a Baker's cyst, or potentially a Deep Vein Thrombosis (DVT), which is a serious blood clot requiring urgent evaluation. For temporary relief, over-the-counter pain relievers like ibuprofen or acetaminophen may help, provided you have no contraindications. However, because constant, radiating leg pain can stem from vascular or nerve issues, I highly recommend consulting a healthcare professional promptly for a physical exam and imaging (like an ultrasound or MRI) to establish an accurate diagnosis and safe treatment plan.