John - I have had bouts with the same thing. It took me a few years to develop a protocol that seemed to be effective, but every year for the last 6-7 years I've had to deal with an annual war against sinus infection or sinus fungus. The cool thing has been to see how much more effective the protocol is using doTerra oils.
The turning point for me is when I learned to use a nasal irrigation devise or Neti pot. This was hard for me because the methods of moving liquids through my sinuses were very uncomfortable for me. I had a near drowning experience when I was a child, and as I used the irrigation method, I would encounter very vivid feelings that resembled drowning.
It has become very second nature to me now, and I use it at the first sign of sinus problems. I mix 2 cups of warm water with 1-2 teaspoons of quality sea salt to make a saline solution. Then I add 4 drops of eucalyptus, 2 drops of rosemary and 2 drops of frankincense. I irrigate at least twice a day, sometimes more, and the I put breathe on my neck and along my nostrils. Finally I take a capsule of 4 drops oregano, 4 drops on guard and 4 drops frankincense. I do this three times daily. It usually takes about 3 days of the protocol, and I do it more if I still feel effects.

Independent Product Consultants #1070
Mix approximately 2 cups of hot water with 2 teaspoons of quality sea salt to make a saline solution.
For Congestion or sinus issues, add 4 drops of eucalyptus, 2 drops of rosemary and 2 drops of frankincense to the saline and blend in a blender for about 1 minute.
For Allergies, consider 2 drops of Lemon, 2 drops of Lavender and 2 drops of Peppermint to add to the saline.
Place the blend in the Neti Pot, and when the temperature is bearable, pour through one nostril, letting the blend run through your sinuses out the other nostril. Repeat this procedure twice per day or as needed till symptoms are gone.
Also consider the blend breathe with the saline for sinus or congestion problems.