Honestly, it sounds like you do NOT have chronic sinusitis.... From what you've said, my opinion is that you may either have some allergy issues --- whether airborne or food-related, that are causing your occasional symptoms... and/or stress-related tension headaches... stress only exasperates all of our health issues... I'm in the restaurant bizness, and my symptoms ALWAYS get worse when I'm under stress, which happens more often than I would like... ha!
Seriously -- if you had chronic sinusitis, you would have said, "Man! I suffer from MOST of those symptoms"!!!! In my post, I said I have few or no symptoms, because my symptoms are relatively mild and infrequent... but they always come back... they recur regularly... I have a flare-up about once every 5-6 weeks.... I've figured out that the source of my problem is my cat... I'm doing Liver Flushes and possibly beginning imunotherapy soon to help with that... cuz I'm not giving her up!! Ha!
Here's a great link that will explain sinusitis.... After you read it, you'll realize how lucky you are to have only those few symptoms that you describe... and to not have to deal with this issue on a daily basis... There are MANY more websites out there on the subject, as something like 32 million Americans suffer from chronic sinusitis!!! http://www.mayoclinic.com/health/chronic-sinusitis/DS00232
Good luck with your headaches!! Try to relax a little every day... quit caffeine completely (if you drink it) and take some relora... it lowers your cortisol levels naturally and helps you get through those tough times... get a massage... meditate... etc., etc... Sorry -- not trying to preach, but those things have helped me immensely -- ESPECIALLY the no-caffeine thing...