I also have this problem. The pain at the left back of my head was so severe. I tried many kinds of herbal nasal drops in Nepal, but couldn't cure it. Then I went to a doctor. I took medicine for some months, again couldn't cure it. The doctor told me it needed surgery. I am planning for that. But after reducing alcohol intake (to almost zero), it has improved a lot. Phatte, reduce your drink and smoking (if you do) along with taking medicines. It will help, at least for me it helped.