Headache due to sinus. Okay? is it?

I am diagnosed with DNS but its not too much deviated. Sometimes its running nose and suddenly it becomes blocked. I generally put otrivin drops in nose to open blockage. It works most of time. But severe headaches and pain above eye is very frequent. It occurs sometimes during running nose and sometimes during blocked nose. I read somewhere headache and pain is due to dryness in sinus. My query is - 1. is frequent use of otrivin okay? As it may help to lubricate sinus. I am not even sure if it works everytime to reduce pain. 2. Any other way to remove dryness and ease the pain in head and above eyes. I drink water regularly but somehow its not helping. 3. Any recommended nasal drops which i can use for reducing pain. Somebody told me distilled warm water with pinch of salt and sugar works as drops. Is it?