You might be having sinus/allergy issues. I found that sinus irrigation works extremely well at relieving symptoms. Its a little strange at first, but I do it every AM and PM. Sometimes the stuff that comes out my nose is disgusting, but it makes a huge difference. It does take several weeks before you notice any immediate difference other than congestion relief, which tends to be immediate. I use one of these now.
http://www.epinions.com/reviews/Ayr_Sinus_Rinse_Kit_Saline_Sinus_WashAs for chiropractic, I am pretty much convinced it is 50% voodoo, but it tends to work pretty well for certain problems. I am not real thrilled that I have to go periodically to get more adjustments, but the near instant relief I get when my neck or back is sore is well worth it.
Amazingly, before I discovered sinus irrigation, I used to go when I had sinus and allergy issues. I never have figured out what it was but, the guy had the knack of tweaking my neck that caused my sinuses to start draining. Once I went there I had a sinus infection that had been going on for several weeks. I had gone to an immediate care clinic and got an antibiotic and decongestant Rx. Was doing nothing. Went to chiropractor because my neck was sore. He said he might be able to help my sinus problem Don't have any idea what he did, or why it worked but by the time I walked out to my car, my sinuses had started draining.
Between the chiropractor and sinus irrigation, I have not had to go to a regular MD for sinus problems for 3 or 4 years now. Thats a record for me.