It sounds to me like your sinus and infection problems might be symptoms of an underlying cause. Have your drs ever talked to you about food allergies/sensitivities, nutritional deficiencies, or a systemic candida infection being the cause of your problems? I'd suggest getting a full nutritional panel run (vits/mins) along with a test for candida.
Rather than going through the expense and pain of allergy testing, you might consider reading up and trying an Elimination Re-Challenge Diagnosis diet. Its where you eliminate certain common allergy-causing foods from your diet and then reintroduce them one at a time. I strongly suggest trying this, after reading up on how to correctly do the food re-introduction.
Food sensitivities can cause all kinds of reactions and not just the ones we first think of. Reactions may be delayed for 12 up to 72 hours after eating.
They can cause: chronic headaches, sinus headaches,
migraines, difficulty sleeping, dizziness, red face, runny or stuffy nose, post nasal drip, ringing in the ears, red ears, earaches, vertigo, blurred vision,
eye pain, dark circles under eyes, bad breath, geographic tongue, mouth ulcers,
recurrent upper respiratory infections and colds, recurrent ear infections, irregular or rapid heart beats, palpitations, high blood pressure, asthma, wheezing,
chronic cough, colic (in infants), nausea and vomiting, diarrhea, loose stools, constipation,
irritable bowel syndrome, colitis (Crohn's Disease and Ulcerative Colitis), reflux, heartburn, indigestion, gall bladder conditions, malabsorption syndromes, cystitis, interstitial cystitis,
recurrent urinary tract infections, blood in urine, nephritis, glomerulonephrosis, recurrent vaginitis, PMS, hives, eczema, psoriasis, acne, muscle and joint pain, arthritis, lupus, muscle weakness,
fatigue, hypoglycemia, starch and sugar cravings, hyperactivity and attention deficit, behavior problems, learning problems, convulsions, bulimia, obesity, anxiety, panic reactions, depression, mental dullness, memory lapses, mood swings and irritability, anger outbursts, difficulty thinking.
Any of this stuff sounding familiar?
Now while some of the above-listed are autoimmune disorders, chronic exposure to sensitivity-causing foods can trigger such disorders, especially after an infection or illness.
Just so you know, I was also recently dx'd with PCOS. My dr has emphasized that I cut all refined sugar and flour out of my diet and, instead, eat a diet of 1/2 veggies, 1/4 complex carbs, and 1/4 protein. I'm also doing the Elimination Re-Challenge diet because I've had some chronic health problems since I was a child (in my 40s now) and nothing else is working.
Good luck and please keep us posted.