? sinus headache... maybe sinus inf with clear nasal dicharge? Just a thought!
In the absence of other central nervous system issues, I really would not fasten on a cerebral spinal cord fluid leak. That is highly unlikely.
Sinus discharge is much more probable, and totally harmless, if annoying.
csf wouldn't find it way into your nasal cavity. its a pretty closed system until you puncture it with say an LP needle.
If you are concerned I say see your GP. We are not doctors so that would be my suggestion. If it is sinus they may make suggestions. They used to put everyone on antibiotics but there are other options. If you go to the drug store and get plain nasal saline and use it constantly while you are having issues that helps, plus gargling with salt water. Drink plenty of water. Water will thin mucus and flush any bad stuff out of your cells. Decongestants often make things worse. I have had sinus issues all my life and Doctors told me salt and water are the best things. Salt kills the bug and shrinks the tissue and water flushes everything out.