Hello!
You could try taking decongestants like Tylenol sinus or Advil sinus. This may help with the congestion and headaches. Also, if the cough is due to nasal discharge in the throat, that might help too. You can continue the sinus rinse.
If the cough is too uncomfortable, you can combine it with a DM cough syrup. However, if you have difficulty breathing or pain in your chest or back, it would be better to consult a doctor. If you have a history of asthma, the syrup would not be recommended.
**CAUTION, some syrups and cold tablets may contain more than one similar medication. Avoid duplicating ingredients. I recommend that you ask at the pharmacy to be sure. Personally, I prefer to recommend the cough syrup and the decongestant separately so that you can take them as needed depending on the evolution of your symptoms. However, it is possible to take a tablet that contains all of these together.
I advise you to consult a doctor if the nasal congestion and sinus pain do not improve after 7 days (since the beginning of the symptoms, i.e. in 2 days for you) because it is possible that an antibiotic against sinusitis will be prescribed. Sinusitis is often viral and usually gets better without treatment. However, if the symptoms do not improve in 1 week, it is possible that it is bacterial and at that time the antibiotic can help. You should also consult if the cough persists after 3 weeks.
I hope this is helpful to you,
Marie-Laurence Gauthier, pharmacist.