I am confident I have a sinus infection, but I live out of a metro area and cannot reach my doctor.  I was recently treated for an upper respiratory infection with a z pack and cough medicine which has improved; however, I awoke two days ago with pain in my neck that has now settled in my head, behind my eyes.  The pain is such that I have severe nausea and am dizzy.
Hi. Welcome to Chat Doctor . I have gone through your query and can understand your concern. As per your complaint the symptoms seems to be due to Frontal Sinusitis leading to headache and pressure behind the eyes and nausea and dizziness can be due to infection and pain. I would suggest you to take a course of antibiotics like Augmenting, anti-inflammatory painkillers like Ibuprofen, decongestants like Pseudopod Chat Doctor. . You can also do steroid nasal sprays and nasal decongestants like Xylometazoline. For nausea, you can take Risperidone. Hope this information helps. Thanks and regards.