The fact that funguses are the cause of most sinus issues was really driven home to me after I took antifungals, including Humaworm, for a candida infection, and my sinus problems totally went away. (Even though Humaworm is known to be antiparasitic, it also has a lot of very effective antifungals in it.)
Unfortunately, despite the Mayo Clinic study, modern medicine often prescribes Antibiotics for sinus problems, which can make the situation worse because Antibiotics kill off the good bacteria which competes for space in your body with the funguses. Cortisone nasal sprays can also be problematic because cortisone reduces the body's immune system's ability to fight funguses. Cortisone nasal sprays even include the warning not to use them if you have a fungus infection. So, if you have a history of Antibiotic or cortisone use, you may want to check out the possible fungal connection to your sinus problems.
Good luck, and it's wonderful that you are taking control of your own health at such a young age!