What Causes Recurring Cold And Sinus Headaches Along With Light Headedness?

I keep getting a recurring cold and sinus headache, light headedness and sometimes accompanied by a slight upset stomeach and fatigue. This has been going on for almost a year now. I'm already barreling with all the supplements I take and they don't seem to help. I have to take" ft least a day off work each time this happens. This cannot go on. Help please!
Ps - the sinus xrays I had are clear apparently.