Your symptoms are typical of chronic sinusitis. A coronal CT of the sinuses and/or fiberoptic nasal endoscopy is diagnostic for it. Some physician may recommend nasal smear also to differential the allergy and infection. The aim of treatment is; relieve the obstruction, treatment of the infection, if present, thinning the mucus, and opening the sinus. Following would be the treatment protocol;
1) Nasal steroid; decrease inflammation and open up obstruction.
2) Oral decongestants such as pseudoephedrine are often helpful.
3) Topical decongestant for short duration.
5) Steam vaporizer
6) Eucalyptus oil may help
7) Nasal saline irrigation
8) Vitamin C
9) Antibiotics; only if nasal culture is positive and there are signs in CT scan.
For treating it naturally; steam inhalation, nasal saline water (salt water) irrigation (can be done by Neti-pot), Vitamin C, Eucalyptus oil inhalation can be done. Following can increase the body immunity so help in overcoming the sinus infection;
1) Omega 3; Fish oil capsule and flaxseed oil capsule.
2) Ginkgo Biloba
3) Zinc 30 mg.
You may also be looked for GERD, which has increasingly been implicated in causing or exacerbating chronic sinusitis. The exact relationships and mechanisms are presently a matter of speculation, though. GERD can not only cause sinusitis but also a condition called as reflux laryngitis. Your voice symptoms point to reflux laryngitis. Following investigations may be able to confirm it;
1) Barium esophagography
2) Ambulatory 24-hour pharyngoesophageal pH monitoring
3) A biopsy of the larynx which may show laryngitis.
Following specialists are needed to work in tandem for treatment;
1) ENT specialist
Following measures are helpful:
1) Small 5-6 meals a day.
2) Last meal should be eaten 3 hours before lying down.
3) Avoid; fried or fatty foods, chocolate, peppermint, alcohol, coffee, carbonated beverages, citrus fruits or juices, tomato sauce, ketchup, mustard, vinegar.
4) Eat slowly so air is not swallowed.
5) Swallowing therapy by a speech-language pathologist.
6) Lose weight if obese or overweight.
7) Elevate the head of the bed by 6 inches.
8) Avoid tight clothing.
9) Stop smoking, if you do.
Please see the resource;
Please feel free for your follow up questions.
I would be happy to assist you further, if you need any more information.