If you are having a significant amount of sinus pressure and pain, then it would suggest that the sinuses are involved. There are certain infections that can affect the entire respiratory system, including the nose, sinuses, and airways in the lungs. If there is a fever, then that would strongly suggest an infectious process, rather than irritation from reflux.
There are several interventions that can be tried at home. Irrigation of the nose and sinuses with warm saline water is reasonable. If the Ocean spray is of limited benefit, then it may work better to perform large volume irrigation of the nose and sinuses, such as with a Netipot. It also may help to try a decongestant, and since the Benadryl made the pressure worse, it would be better to use a decongestant alone, such as phenylephrine.
When symptoms persist for a week, it is also appropriate to consider whether antibiotics are needed. The current recommendations are to try to avoid antibiotics initially, as most infections will resolve with supportive care. But the people in whom antibiotics would be appropriate would be individuals with more severe or persistent symptoms. However, antibiotics would require a prescription from your doctor. It would be fine to try large volume irrigation and decongestant use first, but if the symptoms persist, then it would be appropriate to consider antibiotics.
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